and Laboratory Methods. 



1363 



characteristic of the tail to form coils, which were often seen to surround the head, 

 and if the smear be at all thick these coils render it impossible to outline the 

 individual cells. An abrupt bend, at right angle, which extends for but a short 

 distance and then forms another equally abrupt angle to assume the course pre- 

 viously taken, was a common finding. This irregularity in the course of the tail 

 may be seen near the head, but more commonly at the junction of the first and 



second thirds. 



Total length, . . 0.051 to 0.066 mm., or 0.002 to 0.0025 in. 



Length, head, . . 0.006 to 0.009 mm., or 0.0002 to 0.0003 in. 



Width, head, . . 0.003 to 0.004 mm., or 0.0001 to 0.0001 in. 



Length, tail, . . 0.045 to 0.058 mm., or 0.0017 to 0.0022 in. 



In studying the spermatozoa of the horse (Fig. 4) it was observed that their 



general characteristics and reaction to stain were similar to those of man, except 



that after the fluid had been kept for a few days the tails of certain cells appeared 



to be fibrillated. The measurements of equine spermatozoa were found to be : 



Total length, . . 0.064 to 0.067 mm., or 0.0025 to 0.0026 in. 



Length, head, . . 0.0(»6 to 0.008 mm., or 0.0002 to 0.0003 in. 



Width, head, . . 0.003 to 0.004 mm., or 0.0001 to 0.0001 in. 



Length, tail, . . 0.054 to 0.060 mm., or 0.(H»21 to 0.0022 in. 



Fig. .5. — Bull. Fig. 6. — Mouse. 



The spermatozoa of the bull (Fig. 5) were always accompanied by many free 

 heads, and comparatively few free tails. The head of each spermatozoon stained 

 feebly except for a small portion at its junction with the tail (centrosome), which 

 stained deeply. The tail was always found to be well stained ; its course rather 

 irregular ; but never was it seen to change abruptly, as was commonly observed 

 in the rabbit, nor did it ever extend in a direct course from the head, as is the 

 rule in man and in the horse. The measurements of bovine spermatozoa were 



found to be : 



Total length, . . 0.087 to 0.093 mm., or 0.0033 to 0.0036 in. 



Length, head, . . . 0.009 to 0.009 mm., or 0.0003 to 0.0003 in. 



Width, head, . . 0.006 to 0.006 mm., or 0.0002 to 0.0002 in. 



Length, tail, . . . 0.077 to 0.083 mm., or 0.003 to 0.0032 in. 



