AGRICULTUEAL BOTANY. 529 



author thinks it possible that the proLoplast couUiius invisible organs, but that 

 the development of the organism depends quite as much on their response to 

 stimuli as to their actual form or chemical nature. Whatever the origin of 

 new forms, their survival, he claims, depends uiK)n natural selection. 



The variegation of leaves and its transmission through grafts, E. Griffon 

 {Bui. Soc. Bot. France, 58 {1911), No. 4-5, pp. 289-297).— A discussion is given 

 of the possibility of transmitting variegation to stock from scions, and the 

 author gives the results of investigations which have been carried on for 

 several years at Grignon, in which a considerable number of variegated orna- 

 mentals have been grafted on green stock of the same species. 



He claims that his investigations confirm those of others which show that 

 plants with colored leaves react toward the stock in different ways. When the 

 color of the leaves is red or violet, indicating the presence of anthocyanin in 

 the cell sap. the variegation is not transmitted by the graft to the leaves of 

 the stock, nor is the white variegation commonly transmitted. However, when 

 the variegation is yellow, especially when the leaves present a marbled ap- 

 pearance, it is nearly always transmitted by the graft. In this case the results 

 agree with the conclusions of Lindemuth and Baur (E. S. R., 20, pp. 131, 1047) 

 regarding what is called infectious chlorosis. 



A botanical study of some varieties of Solanum tuberosum and of related 

 wild species of Solanum, P, BEP,TH.AtrLT (Ann. Sci. Agron., 3. ser., 6 {1911), 

 II, yos. 1, pp. 1-59, figs. 20; 2, pp. 87-1^3, figs. 16; 3, pp. 173-216, figs. 12, dgm. 

 // 4, PP- 2-'f8-291, pis. 9, figs. 3). — Anatomical and morphological studies were 

 made of about 350 varieties of cultivated potatoes and of 35 species of Solanum 

 that are more or less closely related to 8. tuberosum, the object being to learn 

 if possible the origin of the cultivated potato. 



The author claims that the cultivated potato differs from all the spontaneous 

 species of Solanum and that its ancestry was probably a S. tiihcrosum which 

 was a spontaneous variation now very rare or long since disappeared. The 

 only species that closely resemble the cultivated potato are believed to be 

 aberrant forms or possibly hybrids of S. tuberosum. 



On the parentage of a wheat, B. Kajanus {Bot. Notiscr, 1911, Xo. 6, pp. 

 293, 29.'i). — The splitting into several types of a stock of wheat (Triticum 

 turgidum) under observation called attention to a supposed spontaneous cross- 

 ing occurring probably 4 years ago. The parentage on the male side is in 

 doubt, being attributable to T. vulgare or to T. spelta. Although von Tscher- 

 mak found on crossing T. vulgare with T. spelta that the posterity resembled 

 T. spelta rather than T. vulgare in the ratio of 3:1, the author believes that 

 these descendants show the inverse ratio of more or less resemblance to 

 T. spelta as opposed to uonresemblance. He considers T. spelta as probably 

 the male parent. 



Concerning a new species of shepherd's purse, P. Becquerel and S. Buchet 

 (Bui. Soc. Bot. France, 58 {1911), No. 4-5, pp. 376-380). — A discussion is given 

 of the origin of a species of Capsella, called by Blaringhem C. vigiiieri, which 

 very often bears 4 carpels. This species has been held to be a mutant from the 

 common C. bitn'sa-pastoris, but the authors in their discussion seem to be 

 inclined to doubt its reputed origin or recent appearance. 



Anatomical researches on cactus from the viewpoint of its being adapted 

 to a dry climate, J. Bedelian (Nnovo Gior. Bot. Ital., n. ser., 18 (1911), No. 

 4, pp. 399-458, pis. 3). — Sixty-three species included in 14 genera of cacti from 

 the botanic garden at Palermo were examined as to peculiarities of structure, 

 and also with regard to the character of the cell contents as related to the 

 absorption, retention, transmission, and ti'anspiration of water. The species 

 are described in detail and numerous measurements are given. 



