318 



C. M. CHILD. 



mental conditions to heads without pharyngeal or postpharyngeal 

 regions. 



2. Normal. (Figs. 2, 3, 4, 6.) In larger pieces these are all 

 much alike (Fig. 4), but in smaller pieces they differ according 

 to the region of the body and other internal and external factors. 



I/ 



A 



v 



Short pieces from the anterior region produce normal wholes 

 like Fig. 2, those above a certain size from the pharyngeal region 

 or immediately posterior to it produce wholes like Fig. 3. 



3. Teratophthalmic. (Figs. 9-23.) Abnormalities of the eyes 

 are frequent in regulation of pieces of Planaria and their occur- 



