ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 65 



course to the under side of the petiole ; the rest pass obliquely upwards 

 to the cortex and base of the leaf, forming two characteristic girdles. 

 The two direct strands may also unite with two dorsal strands at the 

 base of the petiole, so that in the older seedhng and adult stem the 

 whole of the fibro-vascular system may be reducible to the two main 

 horizontal strands and their associated lateral traces. S. 0. 



Internal Stomata in Fruits. — H. F. Bergmax {Bull. Torr. Bot, 

 Cluh, 192(1, 47, 213-21, '.) figs.). The author has examined the fruits of 

 various species of Ericace^, and also of Grinum asiatlcum, Sympliori- 

 carpos 7'acemosHs, and Canna sp., and finds that stomata are present in 

 the endocarp ;"the guard-cells contain cliloroplasts, and the stomala are 

 of the same type as those on the other parts of the same plants, except 

 that theyJiave a tendency to be misshapen. Observations carried out 

 under different conditions of light, humidity, and temperature prove 

 that in most cases these internal stomata remain always open, and are no 

 longer functional, but are hereditary survivals of the leaves which have 

 been modified to form the carpels. S. G. 



Physiolog'y. 



Formation and Utilization of Fats in Germination and Matura- 

 tion.— E. F. Tp^rroixe {Ann. Sci. Nat. {But.), ll»20, 10, No. 2, 1-68). 

 The most striking feature in the physiology of these two inverse pro- 

 cesses in oily fruits and seeds is the symmetry of the mechanism involved. 

 During germination the first process in the formation of neutral fats is. 

 saponification accompanied by the production of fatty acids ; in the 

 lipogenesis which immediately precedes maturation of the fruit or seed 

 neutral fats and free fatty acids accumulate. In germination saponifica- 

 tion results through the agency of a lipase which is only active if 

 sufficient water is present ; in lipogenesis the same results can only be 

 brought about if the seed or fruit is dry. In germination the formation 

 of fat is accompanied by a regular decrease in the iodine index, thus 

 pointing to the prior production of the less saturated fatty acids. In 

 lipogenesis the regular increase of the iodine index indicates that the less 

 saturated fatty acids are formed at a later stage. During germination 

 fats are formed from carbohydrates, and the same appears to be true 

 during lipogenesis. In germination saccharose is the first sugar formed, 

 and the only sugar present in the ripe, resting seed is saccharose,. Thus 

 the first and final stages in the formation and utilization of fats are clear, 

 but so far there is no evidence as to the intermediate stages, and at no 

 stage has it been possible to detect the presence of such bye-products as 

 glycerine. This uncertainty as to the intermediate metabolism should 

 form a fruitful subject for future investigation. S. G-. 



General. 



Relative Effectiveness of Cross- and Self-fertilization. — Y. Emotq 

 {Joiirn. Coll. ScL Tohijo, 1920, 43, No. 4, 1-31, 4 tables, 2 pis.). A 

 large number of plants were examined in order to ascertain the relative 



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