Worms (11th Rank)

These are animals:

• with soft, long bodies
• without a head, eyes, articulated limbs, a longitudinal marrow, and a system of circulation

I classify 2 kinds of worms:

1. intestinal

These do not have any vessels for circulation

2. non-intestinal

The worms must:

• immediately follow the insects
• come before the radiates
• occupy the eleventh rank in the animal kingdom

With them, Nature starts to establish the system of articulations.

• This system is completely developed in the insects, arachnids, and crustaceans.

But the organic structure of worms is less perfect than that of insects because they no longer have a longitudinal marrow, head, eyes, and real limbs.

• This organic structure compels us to put them after the insects.

Finally, the new style in the shape which nature starts in them to establish a system of articulations and to move away from the radiating system in the parts proves that we must place the worms before the radiates themselves.

In addition, after the insects we lose the plan carried out by nature in the preceding classes, that is, this general animal shape which consists of an opposing symmetry in the parts, in such a way that each of the parts is opposite an entirely similar part.

In the worms, we no longer find this opposing symmetry in the parts, and we do not see again the radiating arrangement of the organs, both interior and exterior, which we notice in the radiates.

Since the time that I established the class of annelids, some naturalists have given the name worms to annelids themselves. Since they then did not know what to do about the animals in question, they combined them with the polyps.

I leave it to the reader to judge what affinities and classic characteristics authorize us to combine in the same class a Tenia or an Ascaris with a Hydra or any other polyp.

Like the insects, several worms appear still to breathe by trachea, whose openings to the outside are s type of stigmata. But there is reason to believe that these limited and imperfect trachea are aquatic and not aerial, like those of insects, because these animals never live in the open air and are always either deep in water or bathed in the fluids which contain them.

No organ of fertilization is very distinct in them. Thus, I assume that sexual reproduction has no role with this animal. Nevertheless, it could be possible that, just as the circulation is hinted at in the arachnids, so sexual reproduction is sketched out in the worms. This seems to be indicated by the different shapes of the tail in the Strongylus. But observation has not yet well established this reproduction in these animals.

What we see in some of the worms and what we take to be ovaries (as in the Tenia) appear to be only a mass of reproductive corpuscles which do not require fertilization. These oviform corpuscles are internal, like those in the sea urchin, instead of being external like those in the Coryne, and so on.

The polyps display amongst themselves the same differences with respect to the position of the gemmules which they produce. Thus, it is plausible that the worms are internally gemmiparous.

Some animals which, like the worms, lack head, eyes, limbs and perhaps sexual reproduction, thus also establish, in their turn, the degradation maintained in the organic structure which we are looking into in the entire extent of the animal scale.