be published later. However, he represents a single cell at the “‘spore pole 
1906] CURRENT LITERATURE 73 
A second group, among which are the common cereals and various other plants, 
as Lactuca sativa, Helianthus annuus, Asparagus officinalis, Pinus virginiana, 
Robinia pseudacacia, either all decayed before germinating or germinated and 
then all decayed before being examined. A third group, which includes our 
more noxious weeds, retained their vitality to a considerable degree. The 
_ deeper the seeds were buried the better they retained their vitality. Vitality is 
best preserved, even in weed seeds, when they are carefully harvested and 
stored in a dry and comparatively cool place—W. CROCKER. 
Prothallia and sporelings of Botrychium.—BrUCHMANN?5 has been inves- 
tigating Botrychium Lunaria. Since this species has no means of vegetative 
multiplication, like the adventitious shoots of Ophioglossum vulgatum, every 
sporophyte must have come from a gametophyte. The prothallia are hard 
to find because they are very small (1-2™™ long and o.5-1™™ wide),-and the 
sporelings grow for several years before they reach the surface of the soil. The 
_ prothallia are found at a depth of 1-3°™. In form and general character the 
prothallium of B. Lunaria resembles that of B. virginianum, except that it is 
‘much smaller. BrucHMANN succeeded in germinating the spores and his 
results agree with those of CAMPBELL, who got the two and three-cell stage in 
Ophioglossum vulgatum. Further work upon this aspect of the problem will 
of the prothallium and regards this as the first cell of the prothallium, represent- 
ing the protonema stage. Nearly every prothallium bears an embryo and some 
prothallia have two. The first division of the embryo is transverse. Growth 
is very slow, the sporeling being three years old before it reaches the surface. 
One plate and considerable attention in the text is devoted to the anatomy of 
the mature plant.—CHartEs J. CHAMBERLAIN. 
Spermatozoids of Cycas revoluta.—MrvyakeE*® studied the living sperma- 
tozoids at the island of Oshima (28° 30’ N) in September, and in southern Japan 
(31° 35 N) from the beginning to the middle of October. The diameter of 
the spermatozoids varies from 180 to 210“. The two spermatozoids are sur- 
rounded by a delicate membrane, but it could not be determined with certainty 
whether the membrane belongs to the spermatozoid or is merely the Haut- 
schicht of the protoplasm of the pollen tube. For observing the movements 
the spermatozoids were placed in a 10 per cent. cane sugar solution. The move- 
ments often continued for one to three hours; and in one case for six hours and 
forty minutes, and in another case for five hours and thirty minutes. In some 
cases the spermatozoids were shot out suddenly from the pollen tube, which 
seems to be the method that occurs under natural conditions. The forward 
movement is always accompanied by a rotation from left to right about the 
33 BRUCHMANN, H., Ueber das Prothallium und die Sporenpflanze von Botry- 
06. 
_ chium Lunaria Sw. Flora 96: 203-230. pls. 1-2. 19 
3° Miyake, Ueber die Seema von ee revoluta. Ber. Deutsch. Bot. 
Gesell. 24: 78-83. pl. 6. 1906. 
