136 TRANSACTIONS OF THE [FEB. 12, 
In other cases it is divided into finger-like processes closely re- 
sembling certain stages of the ‘‘ Nebenkern,” as figured and de- 
scribed by Gustav Platner in the cases of Limax agrestis and 
Helix pomatia. Again, it is in the form of a sphere; but in all 
forms it is apparently one and the same substance and can be 
observed in all of the male reproductive cells until finally it is 
found in the mature spermatozoan. 
Cytologists are at present by no means agreed in regard to 
the origin of the male attraction sphere in fertilized ova of dif- 
ferent animals. Fol, Hertwig, Field and others assert, on the 
one hand, that it originates from a centrosome lying at the ex- 
treme tip of the mature Spermatozoan (e. g. in Echinoderms). 
Fick and other investigators have shown, on the other hand, 
that the male attraction sphere is, in some cases, formed from the 
middle piece of the spermatozoan (as in Awolotl). Here in 
the one case there is a certain portion of the spermatozoan—the 
centrosome—which performs a certain function in fertilization. 
In the other case there is, apparently, an entirely different por- 
tion of the spermatozoan—the middle piece—which performs 
the same function. In view of this contradiction and as illus- 
trating the identity, in some cases, of centrosome and middle 
piece, the history of the archoplasm mass in Lumbricus is in- 
teresting and important. 
The spermatogenesis of Lumbricus offers exceptional mate- 
rial for demonstration of the final distribution of the cytoplas- 
mic and nuclear elements. The developing sexual cells, as is 
well known, are here attached to a central mass or spermato- 
sphere by means of which the cells can be oriented at a glance. 
Also the archoplasm mass is quite conspicuous and not difficult 
to demonstrate, provided the proper stains are employed. 
Almost any nuclear stain is suflicient to reveal its presence, but 
Kleinenberg’s haematoxylin and the iron haematoxylin of Hei- 
denhain give the best results. 
Platner, in his work on the spermatogenesis of the butterfly, 
shows that the middle piece of the mature spermatozoan is 
formed from the achromatic verbindungsfaden of the spindle 
after division of the spermatocyte of the second order. The 
centrosome is thus in position at the head of the spermatozoan, 
while the tail is developed from the opposite end. In Lumbri- 
cus the development of the spermatid is quite different. Here 
the spermatid is attached at one end to the spermatosphere, and 
the division plane by which it is formed is radial. That is, the 
long axis of the spindle in the spermatocyte of the second order 
is tangential to the spermatosphere (see figure 6), and, as a result, 
the centrosomes, if present, must lie at the side of the sperma- 
