THE DEVELOPMENT OF APLYSIA PUNCTATA. 497 



The Development of Aplysia punctata. 



By 

 A. j^I. Carr Saiiiiders and Margaret Poole. 



With Plate 22 and 20 Text-figures. 



This work was begun by one of us in the spring of 1909, 

 at the Zoological Station at Naples^ when holding the Oxford 

 biological scholarship.^ Owing to various reasons, the chief 

 of whicli was ill-health, little more was done there than to 

 collect material. It has been completed with assistance iu 

 reconstruction of sections and illnstrations at Oxford in the 

 department of Comparative Anatomy during the winter 1909— 

 10. We must here express our gratitude to Prof. Bourne 

 for the opportunity he has afforded us, and the encourage- 

 ment he has given us to complete the work. 



The bionomics of Aplysia have been described with great 

 care by Carazzi and Mazzarelli. The former deals at length 

 with the deposition of the eggs and their early development, 

 while the latter, in his monograph on Aplysia (14), describes 

 the general bionomics of the genus. The three common species 

 found at Naples are punctata, limacina, and depilans. 

 Carazzi (5), in his Avork on the cell-lineage of Aplysia, made 

 observations on all three, and found little difference between 

 them. Our results refer entirely to Aplysia punctata. 



' I wish to take this opportunity of expressing my thanks to the staff 

 at Naples for their continual kindness during the time I was there, and 

 especially to Professor Meyer and Professor Eisig for their valuable 

 advice with regard to methods. — A.M.C.S. 



