2 84 Allen, — The Spermatogenesis of Poly trichum juniperinum. 
nucleus. It is possible that some of the substance of the apical body is retained 
at the tip of the antherozoid ; but of this there is no direct evidence. 
Except for this possibility, a short portion at the anterior end seems to have 
been formed by the blepharoplast alone. The remainder of the body 
consists chiefly of the metamorphosed nucleus ; and, if the greater part of 
the blepharoplast persists at all in the mature antherozoid, it has become so 
closely appressed against, or united with, the nuclear membrane as to be 
indistinguishable. A certain difference in reaction to stains is observable 
between the anterior end and the remainder of the body of the antherozoid. 
For example, if an antherozoid be stained with safranin and pyoktanin blue, 
its anterior part shows a greater affinity for the safranin, in which respect it 
resembles the cilia ; the rest of the body takes more of the blue stain. But 
there is no sharp line of demarcation ; rather, the reddish stain at the tip 
shades gradually into a purple and this in turn into a blue. 
The cilia are undoubtedly formed of cytoplasmic substance, probably 
similar in nature to that of the blepharoplast. The limosphere and percnosome 
play no recognizable part in the development of the antherozoid, although 
the latter probably persists until a very late period and the former body is 
still present in the cytoplasmic remnants that are attached to the mature 
antherozoid. 
The Structures of the Anprocyte in various Plants. 
Leaving out of consideration the conflicting views concerning the origin 
and homologies of the blepharoplast, which have been discussed in another 
place (Allen, 1912), the results of recent work are in substantial accord as to 
the general features of the history of the blepharoplast and nucleus in the 
androcytes of those plants whose spermatogenesis has been studied. With 
reference to the Liverworts, Mosses, and true Ferns, perhaps the most marked 
difference of opinion that still exists is over the question whether the long 
cord or band to which the elongating nucleus becomes applied is developed 
from the blepharoplast alone, or partly from the blepharoplast and partly 
from a later-formed structure. Upon this point most observers hold to the 
former view — a view with which the present writer agrees. In Equisetum 
and Marsilea (Sharp, 1912, 1914), as in the Cycadales, the blepharoplast, 
instead of simply growing longer, breaks up into a mass of granules which 
later unite to form a continuous thread. While the possibility of a some- 
what similar occurrence is suggested by the rather knotty appearance of the 
blepharoplast of Polytrichum when it begins to elongate, there is no time 
when it is visibly resolved into smaller bodies, The spermatogenesis of the 
Cycadales and Ginkgo is distinguished by the fact that the nucleus does not 
elongate ; at most it pushes out a short beak towards the blepharoplast. In 
these Gymnosperms, too, in contrast with the conditions in Bryophytes and 
Pteridophytes, all the cytoplasm of the androcyte seems to remain as an 
