338 RANDOLPH. 



EXPLANATION OF PLATE I. 



LUMBRICULUS VARIEGATUS GrUBE. 



Fig. I. From a transverse section through an adult spechnen, showing neoblasts 

 and their relative position, x 250. 



Fig. 2. Taken from a preparation made by opening a preserved specimen along 

 the median dorsal line, removing the alimentary canal, blood-vessels and nephridia 

 and flattening out the body wall. The figure extends in the direction of the long 

 axis of the worm, showing the inner surface of the body-wall between the ventral 

 nerve cord and the ventral setae of the left side. It is from a developing tail that has 

 nearly reached the adult condition, and shows the peritoneal cells of ordinary size 

 and the neoblasts, with intermediate gradations. X 600, 



Fig. 3. From a transverse section ■^\-^ mm. thick, the ninth section from the pos- 

 terior end of a tail one day old, showing neoblasts in the median ventral region. One 

 neoblast is dividing. The proctodeal invagination is, as a rule, at first irregularly 

 from the side. X 520. 



Fig. 3a. A less highly magnified view of the same, showing the whole section. 



Fig. 4. From a sagittal section of a tail of one day, showing the region from the 

 alimentary canal through the ventral body-wall. The ectoderm and entoderm are 

 regenerated and a union already effected. The neoblasts are surrounded with a large 

 cell body. The new circular muscles do not appear in the section. The adult nerve 

 cord and muscles end abruptly. X 520. 



Fig. 4a. A less highly magnified view giving the whole of the section from which 

 Fig. 4 is taken. X 130. 



Fig. 5. From a section of the same series as in Fig. 4, passing through the region 

 on one side of the alimentary canal, showing cell division in what appear to be ordi- 

 nary peritoneal cells of the dorsal body-wall. Although the tissue of the whole 

 interior of the section is a crowded mass, it is extremely well preserved and the 

 cells in question have every appearance of being normal as to place and condition. 

 X 520. 



All figures drawn with camera. 



