NOTICES OF BOOKS AND MEMOIRS. 283 



adventitious embryo formation. So important and beautifully 

 original is this result, that were it the only goal reached by the 

 author, he would have been entitled to our sincerest gratitude. 



The nucleus of the fertilized germ does not disapi^ear, as has 

 been supposed, but divides in the usual way ^preparatory to the 

 formation of the second embryonal cell. 



Endosperm is formed in one of two ways ; either, as in 

 Monutropa, from division of the nucleus of the embryo -sac and 

 continued subdivision from the new nuclei ; or, as is generally 

 supposed to be universally the case, the nucleus of the embryo-sac 

 is absorbed, and new nuclei make their appearance in the plasma 

 lining its wall. 



The most remarkable upshot of all these observations is that 

 they have led Strasburger to the conclusion that no comparison is 

 I)ossible between the phenomena inside the embryo-sac of Meta- 

 sperms (^Angiosperms), and that of ArcJdsperms [Gymnosperms), and 

 that his phylogenetic scheme of the evolution of the former from 

 GnetacecB is "more than doubtful." The antipodal vesicles cannot 

 represent a prothallus, the entire germ-apparatus (germinal and 

 auxiliary vesicles) has not elsewhere any similar representative ; 

 the auxiliaries are not to be compared with " canal-cells," smce, 

 iiTespective of function, they are not developed from the germ, 

 neither can the filamentary prolongations be regarded as the 

 germinal spot; moreover, if it be held that the auxiliaries are 

 metamorphosed germs, then there is nothing for it but to consider 

 the filamentary prolongations as rej)resenting the germinal spot, 

 from which they differ entirely in structure, function, and chemical 

 relations. This is a subject which demands the attentive con- 

 sideration of every thoughtful evolutionist, and we cannot but 

 think that our author, who has so greatly distinguished himself 

 among the micro-arcana of Nature, will have something further 

 to say about it. S. M. 



Me. Sereno Watson's Contributions to American Botany, ix. 

 (Proc. Amer. Acad., vol. xiv., July, 1879), contains a revision 

 of the LiliacecE of North America, using the name in the large 

 signification now given to it. As many as 235 species are described 

 under fifty genera. Muilla (an inversion of Allium) is a new 

 genus found for a j)lant (HesperosconUum 1 maritima, Torr.) usually 

 placed with the AllietB, but w^hich has the characters of the Millea. 

 Another new genus is separated from Scluenolirion for S, album ^ 

 Durand, and named Hasthu/sia after Mr. S. C. Hastings, of San 

 Francisco, a liberal promoter of the fine volume on the Botany of 

 California. 



A PAPER ' On British Elms,' by Mr. GT. S. Boulger, is printed in 

 the Scottish Arboricultural Society's Transactions. The author 

 has carefully worked up the botanical literature of the subject, and 

 has endeavoured to see authentic specimens, living or dried, of the 

 numerous described forms. His results do not disturb to any 

 extent the classification of our English varieties, of which he 



