No.1.] BUDDING IN GOODSIRIA AND PEROPHORA. ev Au 
of the larva between the two atrial orifices ; while, on the 
other hand, “les cavités péribranchiales sont . . . delimitées 
en dehors seulement par l’épiblaste,’’ and even this partial 
ectodermal lining arises independently, both in time and 
position, of that which lines the cloaca. 
If there is any value in the suggestion here made that the 
ectodermal fold, s.f, Fig. 36, is comparable to the true cloaca 
of the above-quoted authors, it would not be lessened by the 
rejection of their distinction between cloaca and peribranchial 
cavity in so far as this distinction rests upon their view that a 
portion of the peribranchial epithelium is of endodermal origin. 
But, as already said, I do not regard the suggestion, with 
the only facts that I now have to base it on, as deserving more 
than a mere mention. 
b. The Digestive Tract and its Appendages. 
The Ax/age of the intestine is established at a very early 
stage in the development of the bud. It appears at a point on 
the primitive inner vesicle that is ventral, posterior, and slightly 
tothe lett: 
In the earliest condition seen it is a mere short, simple pro- 
jection growing from the wall of the vesicle, situated in a 
notch, or indentation of its side in the region mentioned. 
Fig. 16, Pl. XIII, representing a dorsal view of a whole bud, 
illustrates the above statements, but it must be borne in mind 
that the bud is seen as a transparent object, and that the 
hypophyseal and intestinal Az/agen would not, as represented, 
be seen at the same level. The notch above mentioned is 
clearly seen in this figure as far as the posterior side of the 
vesicle is concerned ; but sections from similar buds enable 
one to see that it is quite as well marked on the ventral side 
as it here appears on the posterior side. Concerning this 
notch, or rather the parts of the vesicle adjacent to it, I shall 
speak further in dealing with the development of the heart ; I 
shall, therefore, leave the subject for the present after mention- 
ing that at o time in the life of the zootd does the digestive tract 
