1917] AGRICULrUEAL BOTANY, 331 



coccifera grown in sun and those grown in sliade are much alike, the stem struc- 

 ture shows differentiation as to its characters. 



Mesophyll structure and function in grains, G. Catai>ano (Atti R. Arcad. 

 Lincei, Rend. CI. Sci. Fis., Mat. e Nat., 5. sen, 25 (1916), I, No. 2, pp. 112-111).— 

 Giving a brief account of studies on some typical leaf structures in gramineous 

 plants, more particularly Chloris gayana, the author states that a sort of 

 differentiation met with in green parenchyma which forms abundant yellow 

 pigment but no starch indicates a degree of specialization in the foliar tissue 

 corresponding to a division of labor in the general process of nutrition, with 

 resulting economy of total resources. 



The nature of the inflorescence and fruit of Pyrus malus, Caroline A. 

 Black {New Hampshire Sta. Tech. Bui. 10 {1916), pp. 519-54T, pls. 8; Mem. 

 N. Y. Bot. Gard., 6 {1916), pp. 519-5^7, pis. 8).— A morphological study of 

 P. malus, including the origin and development of the flower from the incipient 

 shoot and the subsequent formation of the fruit. It deals in considerable detail 

 with the flower bud and its position, the inflorescence, the flower and its essen- 

 tial parts, pollination and fertilization, and the development of the fruit itself. 



It is stated that in the Baldwin apple, which was used in the study under 

 discussion, the size of the fruit bud is not a distinguishing character. The 

 fruit bud, rarely axillary, may occur in various positions, being identified with 

 certainty only by dissection. The growth of the fruit bud is characterized by 

 an elongation of the axis, in which wood is formed and upon which flowers, 

 leaves, and buds develop. The bud scales are modified petioles. The inflor- 

 escence is a simple cyme. The flower parts develop in succession from the 

 torus, the apex of the axis not being completely used up in the production of 

 the flower parts. 



The inferior ovaries are imbedded in the torus, which grows with the carpels. 

 The mesocarp and exocarp of the carpels become fleshy and the endocarp carti- 

 laginous or papery. The torus is the receptacle of the flower and its growth 

 produces the flesh of the fruit, which exhibits a well-defined pith and a cortical 

 layer which are delimited by ten primary vascular bundles, which give rise to 

 the carpellary vascular system. 



The fruit of the apple may be regarded as a reenforced or composite fruit 

 consisting of one or more drupe-like fruits embedded in a fleshy torus. 



The literature cited is listed. 



Notes on parthenocarpy, B. Longo {Ann. Bot. [Rome], 14 {1916), No. 1, pp. 

 29-32, fig. 1). — The author discusses briefly some observations made upon Mon- 

 stera deliciosa and the so-called butter pear, both of which generally produce 

 seedless fruits. 



Department of experimental evolution, C. B. Davenport {Carnegie Inst. 

 Washington Year Book, 14 {1915), pp. 127-149). — Among the principal advances 

 in botany reported during the year are mentioned the discovery that in different 

 strains of Lychnis there is a difference in the dominance of one and the same 

 trait, hermaphroditism (including maleness) ; the proof that inheritance of 

 determiners from both parents by certain plant hybrids leads to more prompt 

 development of characters than in case of inheritance from one side only ; the 

 demonstration of a triple factorial basis for the foliage color of Lychnis ; and 

 the production of a strain of beans with double the number of cotyledons and 

 first leaves of the seedling. 



A new graft hybrid, A. Manaresi {Staz. Sper. Agr. Ital., 48 {1915), No. 5-7, 

 pp. 513-524, P's- 4)- — An account is given of characters noted in a study of a 

 hawthorn said to be a graft hybrid, the probable origin of which is reserved for 

 later discussion. 



