and Laboratory Merhods 2431 



CURRENT BOTANICAL LITERATURE. 



CHARLES J. CHAMBERLAIN, University of Chicago. 



Books for Review and Separates of Papers on Botanical Subjects should be Sent to Charles J. 

 Chamberlain, University of Chicago, Chicago, 111. 



^ „, . e. J- • r,, . Tj u J The hybrid cotton used in this investi- 



CannoD, Wm. A. Studies in Plant Hybrids. ^ 



The Spermatogenesis of Hybrid Cotton. gation was obtained by crossing Gossy- 

 Bull. Torrey Bot. Club, 30: 133-172. pis. .-^^^^ barba dense X G. herbacemn. The 

 7-8, 1903. ^ . . ... 



two mitotic divisions by which the 



microspore mother-cell gives rise to the four microspores are described in con- 

 siderable detail. In practically all anthers of the hybrid cotton, both normal 

 and abnormal conditions are present. In normal microspore mother-cells the 

 first nuclear division is heterotypic and the second homotypic, and the two divis- 

 ions are the exact homologues of these divisions in pure races of plants. The 

 two sizes of chromatin ring or loops found in hybrid pigeons and in some pure 

 forms in plants were not found in the hybrid cotton. The behavior of the chro- 

 matin at the first division could not be traced with sufficient accuracy to deter- 

 mine whether the two daughter nuclei were of pure or of mixed descent. If 

 paternal and maternal chromatin is segregated as a result of the two mitoses in 

 the microspore mother-cells so as to form nuclei with unisexual chromatin, 

 such an organization of the chromatin would constitute a morphological basis 

 for variation in accord with the Mendelian laws. 



Many abnormal cells were observed in the anthers, but these degenerate 

 before the first division of the microspore mother cell. Amitosis is not rare and 

 is probably a factor which leads to infertility. A few mother-cells showed two 

 spindles, as described by other writers on hybrids, but in the hybrid cotton such 

 cells degenerate before the first division is completed. c. j. c. 



Oliver, F. W., and Scott, D.H. On Lai^cnostoma Botanists have for some time been in- 



Lotnaxi, the seed of Lv^iiiodciidroii. ^ ,,. , „ ,/-i. r •, 



terested in the Cycadofilices, a fossil 

 group intermediate between the Ferns and Cycads, but all evidence hitherto has 

 been from the habit and anatomical structure of stem, root and leaf. The dis- 

 covery of seeds belonging in all probability to Lyginodendroii, a prominent 

 genus of the group, supports the conclusions already drawn from anatomical 

 characters. Botanists must be prepared to find that many of the plants classed 

 under Cycadofilices possessed seeds, and that many of the " fern fronds " of 

 paleobotanists belong rather to Spermatophytes. c. j. c. 



Guignard, L. La formation et le developpe- The development of the embryo of 



ment de I'embryon chez Vnyfecoun,. Jour- Hypecoum, One of the Papaverace^, is 

 nal de Botanique, 17: 33-44, figs. 1-20, 1903. '^■^ . '^ 



very peculiar. After the second divis- 

 ion of the fertilized ^^^g., the structure looks like a two celled embryo with a uni- 

 cellular suspensor, but the three cells become separated at this stage, and one 

 of the cells of the apparent embryo gives rise to the entire embryo proper. The 

 other two cells never divide, but become extremely large, the nucleus alone of 



