is nearly parallel to that of the mothcr and as therefore in the sec- 

 tions they are ent transversely, the number of already developed 

 pairs of somites cannot be determined with certainty ; probably 

 it is thrce or four. The blastopore already is divided into two 

 parts. The embryonic area is situated close to one of the egg- 

 poles in the periphery of a large trophic vesicle, composed of 

 an ectodermal and an entodermal cell-layer. The whole embryo 

 at this stage is surrounded again by a thin shell. 



The above mentioned phenomenon of eggs lying free in the 

 body cavity, remembering the condition of Annelids, doserves 

 some special attention. Although characters of the Annelids in 

 the Onychophora can be expected, at first sight the fact that 

 the eggs come free into a cavity, which does not seem to belong 

 to the coeloni, seems to make a comparison impossible. An expla- 

 nation however is given by the ontogeny, as described in African 

 species (Peripatopsis capensis and Balfouri) by Sedgwick '), in 

 an Asiatic species (Eoperipatiis Weldoni Evans) by Evans -) and 

 in the American Perlpaius tr'niidadensis Stiihlm. (Edirardsi v. 

 Kennel) and forquafus v. Kennel by Yon Kennel ^). 



According to the description of Sedgwick each somite of the 

 embryo is divided into a dorsal and a ventral division. The 

 nephridia (coelomiducts) arise from the ventral ones, whereas the 

 dorsal divisions become entirely reduced, except those of the 16th 

 till 20th pair of somites, which give rise to the sexual glands ; 

 from the somites of the 21 st pair, which do not divide, arise 

 the generative ducts. Besides, from the walls of the somites 

 masses of cells and also solitary, amoeboid cells come free into the 

 primary body cavity. The sexnal cells, according to Sedgwick, 

 are first seen in the entoderm of the hind part of the body. 



1) The Development of the Cape Species of Peripatus. Part III. Quart. Jrn. of 

 Mier. Sc., Vol. 27, 1887. 



2) On the Malayan Species of Onychophora. Part II. Quart. Jni. of Mier. Se., 

 Vol. 45, 1902. 



3) Entwicklungsgeschichte vou Peripatus Edwardsü Blanch, uiid Peripatus torquatus 

 n. sp. Arb. lust. Wiirzburg, Bd. 7, 1885, and Bd. 8, 1888. 



