1 7 
years. He says that he is in good health, but has suffered much from the revo- 
lutionary movement, both physically and morally, and that they feel themselves 
isolated from the world. He hopes he may, however, soon begin his scientific 
work again, if peace is made.” 
NOTES ON RECENT BRYOLOGICAL LITERATURE 
Bryophytes with reference to Plant Genetics. — A small but valuable 
text 1 on Plant Genetics by the Coulters, at the University of Chicago, has re- 
cently appeared, and pages 187 to 189 take up a brief treatment of the work 
which has been done in the mosses and liverworts bearing on questions of hered- 
ity. 
In dioecious liverworts, such as Marchantia, the antheridia and archegonia 
appear in about equal numbers, and it was supposed, then, that the four spores 
(tetrads) produced by the spore mother-cell of the sporangium would be equally 
divided as to sex, two of them producing antheridial plants and the other two 
archegonial plants. Noll 2 found that gemmae from antheridial gametophytes 
produced only antheridial gametophytes, and those from archegonial gameto- 
phytes only archegonial ones. Strasburger 3 then worked on Sphaerocarpus, 
in which the four spores of the tetred hang together, and found that the four 
gametophytes produced from the four spores of the tetrad were always two 
antheridial and two archegonial, so that the sexes must be differentiated in 
the formation of the four spores of the tetrad during the so-called “reduction- 
division” of the nucleus of the spore mother cell of the sporangium. 4 
During these reduction divisions certain organs of the nuclei known as 
“chromosomes” split and separate to enter into the formation of the newly- 
formed nuclei, and Allen 6 not long ago claimed that the nuclei of the archegonial 
gametophyte of Sphaerocarpus have one larger chromosome, and the nuclei 
of the male gametophyte one very small one. A monoecious liverwort, how- 
ever, must have both antheridial and archegonial characters in each spore, and 
what happens in some species of Riccia where antheridia and archegonia are 
produced by the same gametophyte but at different times? 
The authors refer to the Marchal’s work on Funaria 6 , a species which, like 
Marchantia , is dioecious. Clipping fragments from young sporophytes the 
Marchals were able to grow these directly into gametophytes, thus leaving 
out of the life-cycle the reduction division. According to theory the resulting 
gametophytes should, of course, all be dioecious, producing both antheridia and 
archegonia, and this was exactly the result obtained. 
O. E. J 
1 Coulter, John M., and Coulter, Merle C. Plant Genetics. University of Chicago Press. 
1918. 
2 Noll. Sitzungsb. Nied. Gesell. Bonn. Naturw. Abt. 1907. S. 68. 
3 Strasburger. Biol. Centralblatt 20 : 657, 1900. and Jahrb. Wiss. Bot. 48 : 427-500. 1910. 
4 See Bryoi.ogist 20: 64-66. 1917. 
5 Allen. Science 46 : 466-467. 1917. 
6 Marchal, El & Em. Bull. Acad. Roy. Begique, Cl. Sci. 1907 : 765-789; 1909 : 1249-1288; 
and 1911 : 750-778. 
