184 General Notes. 
the appropriate name of joint. It seems, in fact, as if such were its 
nature, as a very short refringent and dark band of substance here 
joins the stem and tail together. This band is so much narrower 
than the stem or tail that it appears as if there were a deep notch 
on either side of the tail portion of the spermatozoon at this point. 
Immediately behind the joint, the flagelliform tail is continued 
as that tapering organ^ familiar to all histologists since the time of 
Leeuwenhoek. 
The structure of the spermatozoon is therefore more complex 
than is usually supposed, and the_ following eight parts may be dis- 
tinguished, beginning at the anterior extremity : 
Filament, spore, cup, calyx, stem, joint, tail. 
The following measurements are given : 
Head (spore and cup) long J2V0 in. 5.9 fx 
" " broad ttVo- " 3-4 /^ 
Stem long -^tVo " 4-4 /^ 
Tail from joint to tip -g-^o" " -05 ^^• 
Total, head, stem and tail ^\-^ " .06 mm. 
From what has preceded it is clear that there is great capacity 
for variation. Further, it is probable that this high degree of com- 
plexity signifies that a very considerable part of the spermatozoon 
is of secondary importance, or is rather only accessory to the act of 
fertilization or the formation of an oosperm. The already remark- 
able results of those investigators who have occupied themselves 
with the study of the phenomena of fertilization, must undoubtedly 
be modified when the subject is viewed from the basis of a renewed 
study of the structure and function of the spermatozoon at all phases 
of the process of its union with the ovum. May it not be that some 
important parts of the process of union have escaped observation 
in virtue of the optical difficulties which are involved ? The con- 
sequences of fertilization as the result of union with abnormal sper- 
matoz oa is also worthy of consideration, not only from a purely 
scientific standpoint, but also on account of the possible light it 
might throw upon possible abnormalities so provoked, which even- 
tuate in disease and deformity. Truly, to those who are familiar 
with the great number of forms assumed by the male element 
throughout the animal kingdom, and the very diverse conditions 
under which fertilization occurs, it seems as if Uu Bois Reymond's 
reproach — Ignorabimus — may here remain true. 
may possibly be of advantage to use the word organttla he 
following a suggestion of Mobius. Functionally differentiated 
organs, wnue j 
