1362 



Journal of Applied Microscopy 



0.051 to 0.058 mm., 

 0.004 to 0.006 mm., 

 0.003 to 0.004 mm., 

 0.041 to O.053 mm., 



or 0.00-2 to 0.002-2 in. 



or 0.0001 to 0.000-2 in. 



or 0.0001 to 0.0001 in. 



or 0.0016 to 0.002 in. 



added to the spermatic fluid. Measurements showed the spermatozoon of man 

 to be the smallest member of this series. 



Total length, 

 Length, head, 

 Width, head. 

 Length, tail. 



The spermatozoa of the dog (Fig. 2) presented many features which would 

 readily distinguish them from those of man in the fresh and well prepared speci- 

 men ; but if both were subjected to the action of certain secretions and fluids, or 

 allowed to dry before properly smeared on the cover-glass, great question would 

 doubtless arise as to the identity of either of these cells. A small portion of the 

 head, located at the junction of the tail and head, stained deeply, while the 

 remainder of the head appeared as a homogeneous structure bounded by a 

 rather distinct margin. The tail, too, showed but moderate affinity for stains. 

 The head and tail of an individual cell were occasionally seen to unite at right 

 angles, and a few specimens were observed having two distinct, well formed 

 heads projecting from a single tail. The dog furnishing the specimen for this 

 series weighed 105 pounds, and it was the intention to compare the following 

 measurements with those obtained by the study of spermatozoa taken from a 

 terrier, but such opportunity did not offer itself. 



Total length, . 0.007 to 0.074 mm., or 0.0026 to 



Length, head, . 0.004 to 0.008 mm., or 0.0002 to 



Width, head, . . 0.003 to 0.002 mm. or 0.0001 to 



Length, tail, . . 0.050 to 0.067 mm., or 0.0023 to 



0.0028 in. 

 0.0003 in. 

 0.0001 in. 

 0.0026 in. 



Fig. H.— Rabbit 



Horse. 



The spermatozoa of the rabbit (Fig. 3) possess many features common to 

 those of the dog ; the head, in addition to being narrower, presents a deeply 

 stained area at its junction with the tail, and a less marked deepening of the 

 stain was seen at the other extremity, occupying nearly one-third of the whole 

 head. Between these two stained portions a lighter zone was seen. It is 



