35* BOTANICAL GAZETTE [at^il 



with the Engelman^t herbarium. This unpubhshed and undistributed material, 

 containing about 650 numbers, represents the collections of 1 849-1 851, and 

 proves to be very valuable. It has now been published by Blanicinship,33 who 

 has still further added to the value of the contribution by including also the num- 

 bers of the earlier fascicles not previously enumerated {Plantae Lindheimerianae 

 having been left unfinished at the end of the Compositae); a bibliography of 

 Texan botany; a complete index of all three parts, with modern equivalents 

 and corrections, the nomenclature comforming to the Vienna code; and a most 

 interesting sketch, with portrait, of ''LixDHEiMER, the botanist-editor," from 

 data largely supplied by his aon and daughter.— J. M. C. 



Mutation and geographic distribution. 



guments 



in favor of mutation by analyzing the geographic distribution of the Dilleniaceae, 

 stating that this family is chosen simply because it is the first family in Hooker's 

 Flora of British India "with other than world-wide distribution." The details 

 of the analysis cannot be given here, but the results are intended to show that 

 the theory of mutation greatly simpUfies the problems of geographic distribution. 

 In another short paper^s Willis suggests what seems to be an important 

 consideration in the origin of species of flowering plants, namely, that "while 

 the characters that distinguish species and genera are largely characters of the 

 floral organs, the struggle for existence "is almost entirely among the seedlings 

 and young plants, in which these organs are not yet present."— J. M.. C. 



Fertilization in Polytrichum.— The van Leeuwxn-Reyxva.\ns36 have pub- 

 lished the first account of the details of fertilization in mosses and describe most 

 remarkable beha\ior by the chromatin. In the next to the last division of the 

 spermatogenous cells each daughter nucleus receives six chromosomes, but in 

 the final mitosis only three, so that the sperm contains only three chromosomes. 

 The mitosis which forms the egg and ventral canal cell shows only three chromo- 

 somes for each nucleus. The egg and ventral canal cell become pressed together 

 and their nuclei fuse, forming a nucleus with six chromosomes. Two sperms 

 then unite with this egg, thus restoring the sporophytic number of chromosomes, 

 which was found to be twelve. The full paper with the plates will be awaited 

 with interest.— Charles T. Chamberlain. 



KINSHIP 



Ann. Rep. Mo. 



liot. Garden 18:123-223. 1907. 



3^ Willis, J. C, The geographical distribution of the Dilleniaceae, as illustrating 



the treatment of this subject on the theory of mutation. Annals Bot. Gard. Peradeniya 

 4:69-76. 1907. 



35 Further evidence against the origin of species by infinitesimal variations. 

 Idem 17-19. 



36 VAN Leeuwex-Reynvaan, Mr. and Mrs. Doctors, On a double reduction of 

 the number of chromosomes during the formation of the sexual cells and on a sub- 

 se-iuent double fertilization in some species of Polytrichum. Koninklijke Akad. 

 Wetenschappen 1907:359-365. ^ - ^ 



