INVERTEBRATA, ORYPTOQAMIA, MICROSCOPY, ETC 981 



the first is uncertain — is that the entire large-celled suspensor, with 

 the exception of its narrow basal end, as well as the embryo, is 

 surrounded by an endosperm which develops in the micropylar half 

 of the young seed ; the base of the suspensor itself entirely fills up 

 the narrow pointed apical end of the embryo-sac. 



Latex and Laticiferous Vessels.* — M. E. Faivre gives the 

 following as the main results of a very careful study of latex and 

 laticifcrs in the embryo and seedling of Tragopogon porrifolius. 



The laticiferous vessels are first formed at the same time as the 

 other vessels, in the cotyledons, the plumule, and the radicle. They 

 are produced, like the rest of the vessels, by the union of cells, not 

 as simple intercellular spaces, and then undergo further development 

 by the elongation of jDrotuberances which are already present in their 

 wall ; they are simply or reticularly branched ; their ends are blind. 

 The laticiferous vessels most closely resemble tracheides in their 

 general distribution, and occur in all parts of the young plant ; they 

 are much more numerous in the cotyledons which contain chlorophyll 

 than in the plumule, and still more so than in the radicle. In the 

 interior of the cotyledons they appear at once in ribbon-shaped and 

 reticulated groups. 



As regards the latex itself, the author distinguishes between an 

 original latex (latex primordial), which is formed before the chloro- 

 phyll, and the latex properly so called, which arises at a later period. 



The author believes the latex to be a reserve-material, the essential 

 composition of which is undoubtedly related to that of protoplasm. 

 It consists fundamentally of fats and nitrogenous substances, and is 

 hence of great service to the plant. It ajipears in the plant in 

 its earliest stages of development, and is deposited, like other reserve- 

 materials, independently of the action of light and of the presence of 

 chlorophyll. When the plants are etiolated by the removal of light, 

 they lose their latex, just as, under similar circumstances, the starch 

 stored up as reserve-material also disappears. The yellow rays of 

 light favour the production of latex, just as they do the formation of 

 starch or oil in the chlorophyll-grains. When air is excluded under 

 a high temperature, the phenomena of etiolation are exhibited in the 

 diminution both of tlu; latex and of the protoplasmic reserve-materials. 

 With access of air and a lower temperature, the amount of i)roto2)hism 

 increases, as also, under similar conditions, does the reserve-starch. 

 Difterent soils cause an increase or diminution of the latex, according 

 as they promote or retard the development of the plant. 



Rudimentary Coma in Godetia.f — While investigating the de- 

 velopment of the embryo-sac in the different genera of Onagracea), 

 Mr. J. M. Coulter's attention was attracted to certain hair-like pro- 

 jections which appeared upon the forming ovule of Godctia (probably 

 G. grandijiora). A careful examination showed them to be identical 

 in structure with the forming hairs in the coma of Epili>lnHm. They 

 occurred almost exclusively at the chalazal end, one or two scattered 



• ' Mnii. Acad. Sci. Lyrm,' xxiii. (1878-79) p. 3G1. Sec ' Bot. Contialbl.,' i. 

 (1880)1). 747. 



t 'Hot. Gazette' (hi<liiiim), v. (18S0) p. 7."). Sie ' Natur.,' xxii. (1880) p. 595. 



