Degradation and Simplification in the Organic Structure

The extremes of the chain of animal life are:

• the most perfect animals
• those with the simplest organic structure

One of the most important concerns of Zoological Philosophy is the degradation and the simplification in the organic structures of animals between these extremes.

This is caused by a constant natural law which always works uniformly.

But it varies here and there throughout the entire chain of animal life, through particular causes.

The general series of animals, arranged in accordance with their natural affinities, displays a series of particular groups, resulting from the different systems of organic structure employed by nature.

If these groups are themselves organized in accordance with the decreasing complexity of organic structures, they form a real chain.

In spite of the anomalies from one extremity to the other of this chain there reigns a striking degradation in the organic structures of the animals which comprise it, and a proportional diminution in the number of faculties of these animals.

The result is that, if at one end of the chain in question are the most perfect animals in all respects, then at the opposite end we necessarily see the simplest and most imperfect animals which can be found in nature.

All the special organs are simplified progressively from class to class, are changed, become diminished and weaker gradually, and that they lose the place where they are concentrated, if they are of primary importance, and end up by being completely and utterly done away with, before having reached the opposite end of the chain.

The degradation I am talking about is not always a regularly modulated progression.

For often some organ is missing or changes suddenly, and in its transformations, it sometimes assumes odd shapes which do not link up with any other to any recognizable degree.

Often some organ disappears and reappears several times before being utterly done away with.

But we are going to see that this could not have been otherwise, that the cause which creates organic structures progressively must have experienced various deviations in its products, because its products are often in the position of being changed by a foreign cause which works on them with an efficacious power.

Nonetheless, we will see that the degradation under discussion is no less real and progressive in all the examples wherever we have been able to see it.

If the cause which constantly tends to increase organic complexity was the only one which had influence on the animals’ shape and organs, the increasingly complexity in organic structure would be very regular throughout in its progression.

But things are not like this.

Nature found herself forced to submit her work to the influence of circumstances which operate on it, and everywhere these circumstances made the products vary.

That is the particular cause which brings about here and there in the course of degeneration which we are going to confirm the often bizarre deviations which it presents to us.

Let us attempt to clarify both the progressive degeneration in the organic structure of animals and the cause of the anomalies which the progress of this degeneration manifests along the series of animals.

If nature had brought to life only aquatic animals and if all these animals had always lived in same climate, water, depth, etc., then one would have found in the organic structure of these animals a regular gradation, nicely modulated.

But nature has not confined her power within such limits.

Nature has varied considerably the conditions of the water itself: fresh, salt, tranquil or stagnant, running or constantly agitated, hot and cold, finally, shallow and very deep.

These present special circumstances which have different effects on the aquatic animals there.

The animal races exposed to each of these conditions have been diversified.

Nature produced aquatic animals of all ranks.

• Then she varied them remarkably through the different circumstances given by the waters.

She then led some gradually to live in the air.

• At first, they lived on the waters’ edge
• Then they lived on the dry parts of land in circumstances very different

These conditions so strongly influenced their habits and organs.

The regular gradation which they should present in the complexity of their organic structure was remarkably changed so that it is almost unrecognizable in plenty of locations.

These have led me to a zoological principle: The progress in the complexity of organic structure in the general series of animals undergoes anomalies from the influence of environmental factors and of acquired habits.

People have rejected the progression in the complexity of animals’ organic structure to explain these anomalies.

However, in spite of the apparent gaps (which I am going to point out), the nature’s general plan and the uniform progress in her manner of working, although infinitely various in its means, are still very easy to make out.

To succeed in that, one needs to look at the general series of known animals, first envisaging it in its totality and then in its large groups.

One will see there the least doubtful proofs of the gradation which nature has followed in the design of organic structure, a gradation which the anomalies I have mentioned would never permit one to mistake. Finally one will observe that wherever extreme changes in the circumstances have not been at work, one finds this gradation perfectly modulated in the various sections of the general series to which we have given the name families. This truth becomes even more striking in the study of what we call species. For the more we observe, the more our specific distinctions become problematic, complicated, and minute.

Thus, the gradation in the design of animal organic structure will be a fact which we will not be able to cast doubts upon, since we will have provided detailed and reliable proofs of what has just been outlined. Now, since we are taking the general series of animals in the inverse order to the one nature herself followed in bringing them successively into existence, this gradation is then changed, for us, into a remarkable degradation which governs from one extreme to the other of the animal chain, except for the interruptions which result from objects we have yet to discover and those provided by anomalies produced by extreme environmental circumstances.

Now to establish by reliable facts the basis for the degradation in the organic structure of animals from one extremity of their general series to the other, let us first glance at the total make up of this series. Let us consider the facts laid out before us, and later we will move on quickly to review the fourteen classes which are its main divisions.

In examining the general distribution of animals in the way that I have presented it in the previous section, whose totality is unanimously vouched for by zoologists, who only argue about the limits of certain classes, I call attention to a very evident fact which should be, by itself, already decisive for my purpose, as follows:

At one end of the series (the one which people conventionally consider the anterior extremity), we see animals most perfect in all respects, whose organic structure is the most complex; whereas, at the opposite end of the same series are found the most imperfect animals in nature, those whose organic structure is the simplest and which one suspects are hardly endowed with animal life.

This well acknowledged fact, effectively beyond argument, becomes the first proof of the degradation which I intend to establish. For it is the essential condition for that degradation.

Another fact which arises from a consideration of the general animal series and which provides a second proof of the degradation which governs in the organic structure from one extremity of that chain to the other is the following:

The first 4 classes of the animal kingdom display animals generally provided with a vertebral column, while the animals of all the other classes totally lack this feature.

We know that the vertebral column is the essential basis of the skeleton, which cannot exist without it, and that wherever a vertebral column is found, there is a more or less complete skeleton, improved to a greater or lesser extent.

We also know that the improvement of the faculties proves the improvement in the organs which give rise to them.

Man is beyond ranking because of the extreme superiority of his intelligence.

But our organic structure is an example of the greatest improvement reached by nature.

Thus, the more an animal’s organic structure approaches man’s the more it is improved.

The human body has an articulated skeleton.

• It is everywhere the most complete and improved in all its parts.

This skeleton:

• strengthens man’s body
• provides numerous points of attachment for his muscles
• allows him to vary his movements almost infinitely

The skeleton is the main part in the design of the organic structure in the human body.

All animals with a skeleton have an organic structure more perfect that those who lack a skeleton.

This is why:

• the invertebrates are more imperfect than the vertebrates
• when we place the most perfect animals at the head of the animal kingdom, the general animal series displays a real degradation in organic structure, for after the first four classes, all the animals in those which follow lack a skeleton and are, consequently, less perfectly structured organically.

Among the vertebrates themselves, the degradation is noticed again.

later we shall see that we come across it among the invertebrates. Thus this degradation is a consequence of the constant plan which nature follows and at the same time a result of the order we are following (but inversely).

If we were to follow the order itself, if we moved through the general series of animals going up it from the most imperfect right to the most perfect of them, rather than a degradation in the organic structure, we would find a growing complexity.

We would see successively the animal faculties increasing in number and improvements.

To prove throughout the degradation in question, let us at this point quickly move through the different classes of the animal kingdom.