The Development of the Spermatozoid in Chara. 
BY 
DAVID M. MOTTIER, 
Professor of Botany in Indiana University. 
With Plate XVII. 
W HILE the discovery of the fact that the cilia-bearing part of the 
spermatozoid in Chara and in certain Archegoniates originates 
from a cytoplasmic structure resembling a centrosome has aroused a keen 
interest in the study of spermatogenesis among plants, yet the diversity 
of opinion and the controversies that have arisen concerning the probable 
relation existing between the centrosome and the cilia-bearer, or blepharo- 
plast, have become an equal stimulus to research. Because of the fact that 
in certain Gymnosperms and Pteridophytes the cilia-bearing structure is 
derived from a centrosome-like body, the investigator naturally expects 
to find a similar origin for this structure in the spermatogenesis of other 
plants possessing male gametes that may be called spermatozoids. In this 
respect the expectations of the writer were not realized in a study of the 
development of the spermatozoid of Chara fragilis , and as certain important 
details observed differed from the accounts given by Belajeff (’94) and 
others, the publication of the following seems not superfluous. 
The mature spermatozoid of Chara , as is well known, consists of 
a thread-like body, making two or more spiral turns, and bearing two 
long cilia inserted a short distance behind the anterior end. This body 
is composed of a nucleus occupying the middle portion and a cytoplasmic 
band or thread, the blepharoplast, which bears the two cilia. The blepharo- 
plast, therefore, extends some distance posteriorly as well as anteriorly 
beyond the nuclear portion. 
Up to the present time Belajeff (’94) has given the most complete 
account of the development of the spermatozoid in the Characeae, using 
chiefly Chara foetida as well as species of Nitella . As the earlier part 
of the development described by Belajeff differs somewhat in detail 
from the results of my own observations, a brief outline of the process 
as described by this author will be given first for the sake of greater 
clearness. 
[Annals of Botany, Vol. XVIII. No. LXX. April, 1904.] 
