442 EDWARD E. WILDMAN 
_ refringent vesicles early in the growth period, but he does not 
refer to their origin or behavior. 
Meves, however, finds that they come from the plastosome, as 
we have seen, and he considers them of great importance in 
fertilizaton. He interprets the fact that they fuse with similar 
but smaller granules in the egg as a phenomenon of great sig- 
nificance. Meves was not the first to observe this fusion; as he 
points out (p. 686), L. and R. Zoja (’91) first described it. But 
Meves thinks that these observers missed the significance of it. 
He believes that through the fusion of the plastochondria from the 
sperm with those of the egg, the male transmits to the offspring 
all the paternal structural characters that are to be inherited, 
and that these can be inherited in no other way. Thus, Meves’ 
plastochondria agree in function with the ‘mitochondria’ of 
Benda, Duesberg and others; but the former are nuclear in ori- 
gin, while the latter are thought to arise entirely within the cyto- 
plasm. Even if the male pronucleus could be utterly obliter- 
ated before it fused with the female pronucleus, the offspring, 
according to Meves, would show structural characters inherited 
from the father. 
But we may well ask what proof is there for considering the 
plastochondria to be of such great biological importance? Meves 
gives us none whatever except that these granules persist 
throughout the early cleavages. As we have seen these gran- 
ules play the part of inert products in the cytoplasm forming the 
fibers or rays of the cleavage figure, or through their solution 
helping to form the fertilization membrane (Romeis). We are 
entirely without evidence of the great importance of these gran- 
ules in heredity. On the other hand, there seem to be serious 
reasons for doubting the interpretation of them which Meves has 
given. 
a. Inheritance in enucleated eggs. If Meves’ interpretation be 
correct, Boveri’s classic experiment of fertilizing the enucleated 
eggs of Sphaerechinus with sperm of Echinus should yield plutei 
which are not of the pure Echinus type, since the egg plastochon- 
dria should contribute Sphaerechinus structures to the hybrid. 
