E. C. FAUST. 



centrosome such as Paulmier described for this form. This 

 difference might be claimed to exist because of the different 

 staining capacities of Delafield's hsematoxylin, used in the 

 author's preparations, and iron-alum hcematoxylin which Paul- 

 mier employed. However, Meek's preparations of the "ante- 

 penultimate stage" of Stenobothrus, which were stained with the 

 iron-alum haematoxylin, show a distinct chromatic rod and 

 sheath, but no acrosome and a diminishing centrosome. 



Frequency. 



Length in M. 22.68 23.76 24.84 25.92 27.00 28.08 29.16 30.24 31.32 32.40 33.48 34.56 33.64 



FIG. 4. Bimodal curve of variability of chromatic-rod length for ir and il 

 combined. Number of spermatozoa around both modes approximately equal. 

 Almost bilaterally symmetrical. 



Certain spermatozoa of unusually large size were observed. 

 These are the so-called "giant spermatozoa." Such "giant 

 spermatozoa" have been described by Henking ('91), and Wilcox 

 ('95) f r various species, and by Paulmier ('99) for Anasa tristis. 

 Paulmier described those of "double and quadruple" the normal 

 size, and attributed the phenomena "to the non-completion of 

 one or both of the spermatocyte divisions." The author has 

 observed only the double-sized forms. They are found in about 

 one per cent, of the measurements. These spermatozoa are 

 about one and one fourth times the length of the average normal 

 spermatozoon, and contain about twice the amount of chro- 



