NOTES ON HISTOLOGY OF LINGULA ANATINA. 11 



the stains suggests that of a muscle. They are stained red with 

 erythrosin, as the blood corpuscles usually are : in very favorable 

 cases in haematoxylin-erythrosin-orange G preparations, they are 

 differentiated from the blood corpuscles and compact bodies (vide 

 infra) by their being stained red, while the latter two become 

 yellow (PI. I., Fig. 10). If the fibres were actually modified 

 nuclei as Beyer maintains, they should be stained green with 

 Biondi-Ehrlich's mixture, while as a matter of fact they be- 

 come a homogeneous red. 



b. Occurrence. 



In the body cavity and the palliai sinus the spindle bodies 

 are found sparingly intermingled with other corpuscles. Among 

 the lobes of the testis they occur in numbers. In the peduncular 

 cavity almost all the floating elements of the fluid are the spindle 

 bodies, which seem to increase in number with age. The reason 

 why they accumulate in this region may, I suppose, be that the 

 spindle bodies are larger than the blood corpuscles and are heavier 

 than the lattter. As to their fate, whether they are retained 

 in the body or at times ejected is quite unknown. 



c Development. 



During the larval life the spindle bodies seem to be produced 

 from any part of both the dorsal and ventral body walls. In the 

 adult, on the other hand, the proliferating regions are restricted to 

 two independent places, as I have already stated. The one is the 

 epithelial ridge and the other is the dendritic organ of Hancock. 1 



1. Beyer ('86) states that the spindle bodies are proliferated from the lateral body wall, 

 but as this region is occupied by the parietal muscle layer, no proliferating zone can exist 

 there. He perhaps means the dorsal and ventral body-walls instead of the lateral. 



