166 ARCHEGONIATES. 
that of my own observations, and from the work of Chamberlain (’99) 
on Pinus laricto and Murrill (1900) on Zsuga canadensis, it seems 
that a similarly constructed nucleus is present in these species. In 
Pinus strobus (Ferguson, ’o1) the structure of the egg-nucleus may 
vary from a most delicate network bearing minute granules to an inter- 
rupted, imperfect reticulum composed of large, irregular, diffusely- 
Fic. 69.—The fusion of the sexual nuclei in Pinus sylvestris.—(After Blackman.) 
A, egg cell showing male nucleus (a) entering female nucleus (4). 
B, later stage in the fusion of the sexual nuclei, parental chromatin masses separate. 
C, male and female nuclei fused, multipolar spindle formed, 
staining elements. It has one large, vacuolate nucleolus and a variable 
number of small nucleoli. 
The sexual nuclei of Pzws on coming together are in the resting 
condition, and as in Cycas, Ginkgo, and Zamza the male nucleus 
penetrates bodily into the female nucleus. Here also the male nucleus 
seems to press with some force against the membrane of the egg-nucleus, 
thereby forming a concave depression in the latter (Fig. 69, A). 
