Spermatogenesis in Mnium affine, var. ciliaris 
(Grev.), C.M. 
BY 
WILLIAM L. WOODBURN, 
Northwestern University , Evanston, III . 
With Plate XXI. 
C ONSIDERABLE interest has recently been manifested in cytological 
investigation of antheridial tissues and sperm-cells of the Bryophyta. 
Inasmuch as quite different results have been described by various writers, 
it has seemed to the author worth while to present here a few observations 
concerning Mnium affine , var. ciliaris . Since Wilson (6), Allen (1), and others 
have quite thoroughly reviewed the literature upon the subject, it seems 
unwise to incorporate here that which would be largely a repetition of their 
work. Only a few points concerning which somewhat different observations 
have been reported may be mentioned briefly. 
In my paper (8) on ‘ Spermatogenesis in Blasia pusilla 1 reference was 
made to Wilson’s work (6) on Mnium , A trichum, and Pellia \ also to 
Allen’s (1) investigation of Polytrichum . Wilson describes for Mnium and 
Atrichum the nuclear origin in the androcyte of a unique structure which 
he terms a ‘ limosphere ’. The latter is composed of rod-like structures 
developed from material passed out from the nucleolus. Two other 
divisions from the nucleolus occur, one forming an accessory body, probably 
similar to the 4 Nebenkorper ’ described by Ikeno ( 3 ), the other functioning 
as the blepharoplast. In Pellia Wilson finds centrosomes and centro- 
spheres present during the last division of the spermatogenous tissue. He 
is convinced that in this case the centrosome persists and functions as the 
blepharoplast. A limosphere and an accessory body are also present 
in the androcyte of Pellia . 
Allen (1) has followed the cytological details of the spermatogenous 
tissue of Polytrichum up to the beginning of the transformation of the 
androcyte. Consequently he did not have occasion at that time to observe, 
if present, the structures referred to above in Wilson’s paper. However, 
during the earlier as well as later divisions of the spermatogenous tissue, 
Allen finds certain interesting structures. Kinoplasmic material becomes 
differentiated as plates which occupy the broad poles of the spindles during 
[Annals of Botany, Vol. XXIX. No. CXV. July, 1915.] 
Gg 
