278 BOTANICAL GAZETTE [APRIL 
BLACKMAN’S WORK. 
After this paper had been practically completed, there appeared 
a very important work on Pinus sylvestris by Mr. Blackman (I. ¢.) 
Since this work has already been reviewed in the March num- 
ber of this journal, only a brief comparison will be made here, 
I can confirm his statements that the pollen tube does not enter 
the oosphere ; that the pronuclei at the time of fusion are not ia 
the resting condition ; that the history of the spindle fibers indi- 
cates that they result from a rearrangement of the ordinary 
cytoplasmic reticulum; and that the number of chromosomes is 
twelve in the pollen mother cell, in the nuclei of the sheath of 
the oosphere (fig. 30), and in other parts of the prothallium. 
My second series (figs. 7-70), on the development of, the 
ventral canal cell, was not observed by Blackman. His term 
maturation is not used, because it already has a definite and very 
different application. The term metaplasm is not used in the 
present paper because the network is regarded merely as a some 
what peculiar mim network. In the development of the nucleus 
of the oosphere, he neither figures nor describes the chrome 
history in detail, but the points mentioned do not indicate ie 
sequence decribed in this paper. He finds the chromosomes ° 
the first segmentation nucleus V-shaped; jig. 22 of this ae 
shows them U-shaped. He figures parallel threads around the es 
segmentation nuclei » although this appearance was occasion 
noted in my preparations, the fibers usually had the oe” 
shown in fig. 23. On the whole, it must be said that, while st 
two papers cover approximately the same ground, the he 
detailed work of each, having been done in different oe ie 
subject, is complementary. The general results, howevel 
to a great extent mutually confirmatory. 
SUMMARY. 
: . soon after 
1. While the ventral canal cell usually disap Pee becomes 
it is formed, in some cases it persists and its a? r develop” 
large as that of the oosphere, passing through a simula 
