NOTES ON HISTOLOGY OF LINGULA ANATINA. 7 



goes so far as to discover two valves in the spindle bodies ! For 

 these lie has evidently mistaken surface depressions which occur 

 not infrequently in the spindle bodies. 



In Bronn's Klassen und Ordunung des Thierreichs the 

 question is raised : " ob nicht diese zellen, bei deren bildlicher 

 Darstellung die Angabe von Vergrösserungsgrades vermisst werden, 

 etwa für Prosospermien oder parasitische Pseudonavicellen zu 

 nehmen worden " (p. 281). This interpretation seems à priori 

 probable. But if the spindle body were a Sporozoon it should 

 contain a nucleus or nuclei in some form or other. Such a 

 structure is not found at any stage under any treatment. 



Morse ('73 b) noticed the presence of the spindle bodies 

 and added that " these are amoeboid in their appearance, and 

 may be seen bending and turning as they course through the 

 more delicate ramifications in the palliai membrane " (p. 25). 

 He advances no view as to the nature and orgin of this body. 



Brooks ('78) also observed the spindle bodies and states 

 that when the bodies are crowded together they give an exceed- 

 ingly faint violet tint. He noticed that " running out from one 

 or both of the pointed ends of many of the corpuscles are long 

 delicate filaments of variable length " (p. 49), and found the 

 bodies, which he supposed to be on point of division. 



Beyer's investigation ('86) made known to us that the 

 dendritic organ of Hancock and the epithelial ridge are equiva- 

 lent structures. Like Hancock he came to the conclusion that 

 the spindle bodies are the spermatophores. He does not seem 

 to have himself studied the structure of the spindle bodies. In 

 no part of his paper does he adduce the slightest evidence that 

 these bodies contain spermatozoa. He refers, however, to the 

 " Spermatogenesis " in a final paragraph. He also mistook the 



