In concluding the account of his remarkable discoveries, Ganin draws attention to the great differences in the formation of the eggs and the germs of these parasites from what occurs in other insects. The egg has no nutritive cells; the formation of the primitive band, usually the first indication of the germ, is retarded till the second larval stage is attained; and the embryonal membrane is not homologous with the so-called "amnion" of other insects, but may possibly be compared with the skin developed on the upper side of the low, worm-like acarian, Pentastomum, and the "larval skin" of the embryos of many low Crustacea. He says, also, that we cannot, perhaps, find the homologues of the provisional organs of the larvae, such as the singularly shaped antennae, the claw-like mandibles, the tongue-or ear-like appendages, in other Arthropoda (insects and Crustacea); but that they may be found in the parasitic Lernaean crustaceans, and in the leeches, such as Histriobella. He is also struck by the similarity in the development of these egg-parasites to that of a kind of leech (Nephelis), the embryo of which is provided with ciliae, recalling the larva of Teleas (Fig. 197 _B_, _C_), while in the true leeches (Hirudo) the primitive band is not developed until after they have passed through a provisional larval stage. This complicated metamorphosis of the egg-parasites, Ganin also compares to the so-called "hyper-metamorphosis" of certain insects (Meloe, Sitaris, and the Stylopidae) made known by Siebold, Newport and Fabre, and he considers it to be of the same nature. He also, in closing, compares such early larval forms as those given in figures 193 _E_ and 194, to the free swimming Copepoda. Finally, he says a few words on the theory of evolution, and remarks "there is no doubt that, if a solution of the questions arising concerning the genealogical relations of different animals among themselves is possible, comparative embryology will afford the first and truest principles." He modestly suggests that the facts presented in his paper will widen our views on the genetic relations of the insects to other animals, and refers to the opinion first expressed by Fritz Mueller (Fuer Darwin, p. 91), and endorsed by Haeckel in his "Generelle Morphologie," that we must seek for the ancestors of insects and Arachnida in the Zoea form of Crustacea. He cautiously remarks, however, that "the embryos and larvae observed by me in the egg-parasites open up a new and wide field for a whole series of such considerations; but I will suppress them, since I am firmly convinced that a theory, which I build up to-day, can easily be destroyed with some few facts which I learn to-morrow. Since comparative embryology as a science does not yet exist, so do I think that all genetic theories are too premature, and without a strong scientific foundation."