224 BOTANICAL GAZETTE [SEPTEMBER 
the effects of various fertilizers, including stable and green manures, upon wheat 
seedlings grown in pots. These were checked by field experiments, the results 
being mainly concordant. Here is presented the largest number of experiments 
yet made under uniform conditions, and while the conditions are still too complex 
for full analysis, the trend of the results is clear. Though in certain cases the 
‘composition of the soil as modified by the fertilizer is an important factor, it is 
rarely so important as the physical change. In very many cases, indeed, the crop 
yield can be as greatly increased by proper manipulation of the soil as by adding 
any sort of fertilizer. The experiments also indicate that the fertilizing of a 
particular field or region is a local problem, since even the same soil “types” 
from different localities show different results with the same fertilizer. (This may 
also be taken to indicate that the basis of classification of soils used by the Bureau 
is unnatural.) 
Everyone who is interested in the growth of plants, either theoretically or 
practically, should read and reflect on these bulletins.—C. R. B. 
Reduction and fertilization in Polytrichum.—The mosses have received 
practically no attention from cytologists. The small nuclei and some diffi- 
culties in technique are doubtless responsible for this neglect. A paper by the 
Drs. VAN LEEUWEN-REIJNVAAN® presents the results of an extended investigation 
of Polytrichum piliferum, P. juniperinum, P. formosum, and P. commune. 
In spermatogenous tissue the nucleus contains a large deeply staining mass 
from which the chromosomes arise. From this mass there is cut off a small body 
which passes out of the nucleus into the cytoplasm and divides to form two cen: 
trosomes, These behave like typical centrosomes, and in the telophase are a 
cluded within the nuclear membrane. At the last mitosis they remain In the 
cytoplasm and become blepharoplasts. At the same time a large piece oy 
matin, which may be called a Nebenkern, is cut off and cast out into the cyto- 
plasm, where it gradually degenerates. 
In the sporogonium the mitoses show 12 chromosomes, 4 long, 4 short, and 4 
medium. In the gametophyte there are 6 chromosomes, of which 2 ar¢ long, 
2 short, and 2 medium. At the last spermatogenous division the 6 chromosomes 
unite in pairs, fusing longitudinally, so that one counts 3 chromosomes. nae 
the sperm contains 3 chromosomes, one long, one short, and one medium. 
the division of the central cell of the archegonium, the ventral canal cell geet 
cell each contain 3 chromosomes, one long, one short, and one medium. ertilized 
two cells fuse with each other, and the egg, formed in this manner, is fi 
by two sperms. The fertilized egg contains 12 chromosomes, 3 from th 
proper, 3 from the ventral canal cell, and 3 from each of the two sper™s: 
6 Van LEEUWEN-REIJNVAAN, J. and W., Ueber eine zweifache ae . 
der Bildung der Geschlechtszellen und darauf folgende Befruchtung mittels . 
permatozoiden und iiber die Individualitat der Chromosomen bei einigen Polyt™ 
arten. Recueil Trav. Bot. Neerl. 4:(pp. 44. pls. 2). 1907- 
