462 THE AMERICAN NATURALIST. [Vor. XXXIX. 
blepharoplast which is clearly analogous to the middle piece of 
the animal spermatozoón. We have no evidence that such events 
ever take place in the eggs of plants. On the contrary we know 
that the first cleavage-spindle in the eggs of spermatophytes 
develops without centrosomes from a mesh of fibrille. Also 
the blepharoplasts of the gymnosperms Cycas, Zamia, and Ginkgo 
remain in the cytoplasm at a distance from the fusion nucleus 
and Shaw's account of the fern, Onoclea, indicates that similar 
conditions obtain there. We know less about the history of the 
blepharoplasts within the egg of thallophytes where the first 
cleavage-spindle frequently has very handsome centrospheres 
and asters (e. g., Fucus and Dictyota). Strasburger (97a) 
pointed out that one of the asters of the first cleavage-spindle 
in Fucus arose near the point where the male nucleus united 
with the female. However, Farmer and Williams (98) believe 
that centrospheres of the first cleavage-spindle in Fucus are 
formed de novo and Williams (:04b) came to the same conclu- 
sion for Dictyota. There are some very interesting features in 
the comparative study that Williams (:04b) has made on the 
and parthenogenetic eggs of Dictyota. The spindle in the par- 
thenogenetic egg is multipolar and develops from an intranuclear 
kinoplasmic mesh and there are no centrospheres. But in the 
It seems then probable that the only structures of the sperm 
that preserve their morphological entity in the fertilized eggs of 
plants are the chromosomes. Whatever may be the relation of 
the blepharoplast and other cytoplasmic structures as stimuli to 
the development of the egg they cannot be regarded as fixed 
factors in the problem of heredity. It is very probable that 
they introduce valuable food material, perhaps important fer- 
