454 



DR. J. F. GEMMILL ON THE DEVELOPMENT OP 



develop and the laterals the next, while the ventrals (sulcars) and 

 dorsals (sulculars) appear almost simultaneously a short time after- 

 wards. Throughout the text-figs, these mesenteries are numbered 

 1, 2, 3, 4 respectively. Attachment of the larva then occurs, 

 and in a week or a fortnight a new mesentery (No. 5) forms in 

 each lateral Edwardsia space, and shortly thereafter a new 

 mesentery (No. 6) in each ventro-lateral Edivardsia space. The 



Text-figure 1. 



Text-figure 2. 

 4 



Text-fieure 3. 



Text-figure 4. 



