457 



The vesicle is an elliptical bowl, inverted, and with thick walls 

 that are invaginated at the mouth and somewhat turned back into the 

 cavity. The walls are highly refractive and so is the material filling 

 the bowl, though represented as dark in the above figure. This bowl 

 is set in the body of the sperm somewhat as a very small inverted 

 cup might be held in the hollow of one's closed hand. • The body of 

 the sperm is clear and more watery looking than the bowl though re- 

 presented as black in the above figure. 



In what we arbitrarily call the bottom of the sperm are some 

 droplets, represented in white in the above figure. By focussing it is 

 possible to trace the lips of the bowl as a continuous elliptical ring 

 surrounding the mouth of the bowl, which is about 3 X 1 /*<• The cavity 

 of the bowl, indicated in dark in the figure, has much the shape of a 

 young mushroom with short stalk and only partly opened pileus. 



After understanding the side views the appearances seen from 

 above and below become intelligible. On focussing down outo the tip 

 of the sperm we see at the level of the line 1, Figure 1 a greyish film, 

 rounded ofl" like a sphere. On a much lower level, 2, there is at the 

 centre a clear, ice-like ellipse that represents the mouth of the bowl, 

 surrounding this a wide, greyish elliptical ring which is the substance 

 of the wall of the bowl, and external to this a wide ring representing 

 the rim of the body outside the bowl. On a lower focus, 3, there is 

 a thin watery expanse with only a few droplets scattered through it 

 and this is the bottom of the sperm beneath the mouth of the bowl. 

 On a focal plane near the top, between 1 and 2, we actually see a 

 central ellipse and three concentric elliptical rings; representing the 

 inner opening of the bowl, the innermost lips of the bowl's mouth, 

 the contents of the bowl, and the outer walls of the bowl respectively, 

 in the above order from the centre outward. 



The above is the structure of the normal sperm from the testis 

 as well as from the vas deferens and also from the Annulus of the 

 female, always provided no liquid is added to it. If however, the 

 sperm is examined in water or in other liquid, the radiated form, such 

 as is shown in Figure 5, is apt to be seen. 



In water, or in crayfish blood, or in the serum as used by Herr- 

 mann, or in about 2 7o NaCl, KNO3 or NaPO^, the change from 

 the closed — up to the expanded form is very rapid and not readily 

 studied. But if the sperm in its normal secretion be compressed 

 under a cover glass and studied with Zeiss 2 mm and oculars 4, 6, 

 J 2, 18 as a very minute drop of water is allowed to slowly diffuse into 

 the spermatic paste some of the sperms may be seen to unfold slowly. 



