A 
IS THE BLEPHAROPLAST A CENTROSOME. 71 
would naturally be done by anyone unfamiliar with their complete 
history. The next reference to them in literature occurs in the writer’s 
first preliminary paper published in June, 1897 (122), in which their 
centrosome nature is questioned. In the writer’s third preliminary 
paper, which appeared in October, 1897 (124), it was shown for the 
first time that the bodies in question originate de novo in the cyto- 
plasm of the central cell, apparently having no important functions 
in the formation of the spindle, when this cell divides to form the sper- 
matids, and after it has served its function in forming the cilia of the 
spermatozoid it disintegrates at the apex of the egg cell, apparently 
having no further function. For these reasons it was concluded that 
the organs were not centrosomes proper, and they were termed //e- 
pharoplasts, because of their special function as cilia-formers. This 
immediately led to controversy, and the question is still unsettled. 
Early in 1898 Ikeno (69, p. 17) stated unreservedly that the centro- 
some-like body in Cycads and Ginkgo is a true centrosome. He said: 
ff we apply this conclusion of Hermann to our case, then it is quite clear that 
the body in question, which corresponds to the middle piece in serving as the cilia- 
bearing thread, is not only similar exteriorly to a centrosome, but is a true centro- 
some, and that the cilia-bearing thread is to be regarded as an enormously enlarged 
centrosome.! 
This opinion is further emphasized by Ikeno in his complete mono- 
graph on the fecundation of Cycas revoluta (70). Hirase, in his study 
of Ginkgo and the attractive spheres formed in the spermatogenous 
cells, also concludes that they are to be considered as centrosomes, 
though, as shown by his figure 18 (61, pl. 8), they remain distinct from 
the spindle, the radiations around the sphere not connecting with the 
radiations around the pole of the spindle in the center of which a 
centrosome should be located, if present. Hirase says, furthermore: 
The attractive spheres which we have just described are different from those made 
known by many scientists heretofore. In the first place, they differ in that they are 
always ata certain distance from the poles of the spindle, and in the second place that 
in the course of karyokinesis they do not divide into two daughter spheres.” 
Guignard also takes the same ground, considering the writer’s 
researches on Zama as proof of the existence of centrosomes in seed 
plants. He says: 
Even though all earlier observations upon the presence of attractive spheres and 
centrosomes in different Cormophytes may be regarded as inexact, one can not doubt 
that the bodies recently described and figured by Webber in the pollen cells of 
Zamia * * * are centrosomes (48, p. 161). 
1Uebertriigt man diese Hermannische Folgerung auf unseren Fall, so ist es ohne 
Weiteres klar, dass der in Rede stehende Koérper, welcher sich zum Mittelstiick 
entsprechenden cilientragenden Faden ausdehnt, nicht nur dusserlich einem Centro- 
som ahnlich, sondern ein wahres Centrosom ist, und dass der cilientragende Faden 
als.ein enorm herangewachsenes Centrosom zu deuten ist. 
? Les sphéres attractive que nous venons de décrire sont différentes de celles signalées 
jusqu’a ce jour par plusieurs savants, en premier lieu, en ce qu’elles sont toujours 
a une certaine distance des pdles du fuseau, et en second lieu en ce qu’au cours de la 
karyokinese elles ne se divisent pas en deux spheres-filles. 
