No. 487] 



STUDY OF THE TUNIC AT A 



459 



my own part, sj)eakin<i; as a .syst('ii»atist, I am fully ])iv])are(l to 

 accept the full consequences of just this outcome. Furthermore 

 I see something of the reach of such consequences. 



The fact about the development of branchial stigmata which 

 seems to me second in significance only to cytoplasmic localization, 

 is that the origin of the epithelium of new stigmata is always 

 dependent on that of preceding ones. The general question of 

 how repetitive parts arise is basal. These results on the l)rancliial 

 stigmata of ascidians seem to be decisive so far. Sclys-Long- 

 champs, Dumas and Julin are specially to be mentioned in these 

 investigations. 



time ago about the origin and fate of the follicle cclis of ihc ascidiaii 



decade, thanks to Floderus.\iancroft, 'Fodarl. and KorotnefV. 



( )rinin of tlu> heart from the ectoderm is affirmed by Salensky. 

 lie treats this along with other instances of ontogenic origin of 

 as( i(han parts in deiiance of rigid germ layer tenets, under the 



has rect>ived no thorough investigation (hninu- the .lecade. 



5. Physiology.— Studies of the degeneration and rejiive 



