No. 492] NOTES AND LITERATURE 



807 



cated plexus of forms as the ferns and pteridosperms of the Paleozoic, 

 it is well nigh impossible to come to a definite conclusion as to the 

 question of the common origin of the cycads proper and Cycadeoideae 

 and the question of the possible relation of these on the one hand to 

 the other gymnosperms, and on the other to the angiospemis. "It is 

 believed in the Cycadeoideae and especially in the persistence in such 

 highly organized plants of the marattiaceous synangium that we get 

 the first unmistakable hint of the nature of angiospenn evolution and 

 the further view would seem to be justified that while the staminate 

 disc surrounding the ovulate axis of Cycadeoidea indicates primarily 

 an evolution terminating, so far as now possible to trace, in the gymno- 

 sperms, the juxtaposition of parts is exceedingly suggestive of the 

 possibility, if not the manner as well, of angiosperm development 

 directly from filicinean forms." 



The discovery that many of the supposed Marattiaceae of the Paleo- 

 zoic are really seed-bearing plants, Pteridosperms, emphasizes the 

 importance of the ^rarattiaceae as the ancestors of the higher seed- 

 bearing types. AVIictlicr or not we may agree with all of the author's 

 conclusions, this m;igiiili<ciit nicinoir iiiiisi rciii.iiii aii iiKhspeasable 

 source of information tor (-vcrv sUKlciir inlcn^^icd in lh(> fascinating 

 problems of the origin of the liigl,ci- pbmts. 



are treated in^a reccnf paprr l.v Mi.s 1. K. ( ';irotli.T> (The Develop- 

 ment of the Ovule i.nd Imm.kiI.' ( .amcioi.huc in (iinkgo. linf. Gaz., 

 4.3, pp. lO-l.W, Vvh. \W7). 'VUr nio.t iinpormnt point brought out 

 in the conrso of this study is \Uv fn. l that a large ani..unt of .■hlorophyll 



only instan<'c known where the endoiperni deveh-ps chlorophyll, 



to the light may turn grecMi. The pajxT is areompanied by two plates. 



Among the most iniporlant of the r.rent papers on tIm' development 

 of the Coniferae may 1m- mentioned 1^^o by I,a^^^ou . ( ianietophytes, 

 Fertilization and Enil.ryo of ( 'ephalotaxus Dnipaei-a. A. A. l.awson. 

 Annals oj Botany, X\l. I'.'OT. The ( iametophyie-^ and l'>inlir\o of 

 the Cupressineie with Special Ixefereiiee to Libocedrns decnrrens. 

 Ibid., XXI, Apl. 1907). 



The first of these papers deals with ('<'pha/nf,ixus' dniparra. In 

 this species the macrospore remains un(nvide<l until a verv short time 

 before it is shed, when it divides into two cells, the tul)e cell and the 

 generative cell. No vestigial prothallial cells are present. After the 



