ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 247 



hence promotes greatly the decomposition of humus in the soil. It 

 transforms cane-sugar into reducing sugar, and has a slight diastatic 

 action. Plates of ivory are corroded by it. The root behaves in many 

 respects like a fungus, in so far as the fungus alters the organic con- 

 stituents of the soil by definite excretions, and causes their more rapid 

 decomposition. This root-secretion does not merely impregnate the 

 epidermis, but is often excreted over it in the form of drops. 



Formation of organic acids in the growing parts of plants.* — 

 Herr W. Palladin deduces from the facts already known respecting the 

 formation of asparagin and of vegetable acids in the course of the growth 

 of plants, that the formation of cellulose in growing organs must be 

 accompanied by a strong elimination of oxygen ; that organic acids are 

 formed in these organs as a secondary product of the re-formation of 

 albuminoids from asparagin and carbohydrates ; and that the water 

 formed in the respiration of growing organs is also a product of this 

 same process. 



Localization of Emulsin in Almonds.f — M. Johannsen states that 

 bitter almonds contain a glucoside, amygdalin, and a soluble ferment 

 called emulsin or synaptase. Having to study the question of the 

 localization of emulsin, the author gives the following as the conclu- 

 sion to his researches, viz. : — That amygdalin and emulsin are localized 

 in different tissues. Amygdalin (which is only found in bitter almonds) 

 is localized in the parenchyma of the cotyledons, and emulsin (which 

 is found in all almonds) is localized in the axile parts of the embryo 

 and in the fibrovascular bundles of the cotyledons. 



(3) Structure of Tissues. 



Development of Stomata. j — Herr E. Immich finds that very good 

 objects on which to study the early development of stomata are the leaves 

 of both Monocotyledons and Dicotyledons, either when just emerged 

 from the bud-scales or at somewhat later stages; the plants specially 

 observed were Syringa, Crataegus, Prunus, Acorus, Scirpus, and Palnue. 

 The careful examination of a large number of cotyledons, especially of 

 many Ouciferas and Compositae, shows, on sections of the epidermis, 

 smaller cells of simpler and very characteristic form, the mother-cells 

 of the stomata. In their external contour these cells are not unlike 

 spherical triangles. They are formed by an ordinary epidermal cell 

 being first divided by a central septum into two segments of equal size. 

 From this wall proceeds a second curved wall to the lower part of the 

 cell, and from about the middle point of this a third at an angle of about 

 60° ; the mother-cell of the stoma being then formed. A nucleus is 

 formed in this mother-cell, and it divides into two segments of unequal 

 size by a division-wall a little above its middle. All this takes place 

 while the seeds are still inclosed in the carpels and in quite a youn^ 

 pulpy condition. 



In the Leguminosae the above course of development occurs in the 

 section Phyllolobae, in which the cotyledons rise above the soil and 

 develope into ordinary leaves (Nelilotw, Lotus, Trifolium, &c.) ; while 

 in the SarcolobaB, where the cotyledons remain benoath the soil (Vicict, 

 Ervum, Pisum), the course is somewhat different. No rudiments of 



* Ber. Deut?ch. Bot. Gesell., v. (1887) pp. 325-6. 



t Ann. Sci. Nat, vi. (1887) pp. 118-26. 



X Flora, Ixx. (1887) pp. 435-46, 459-66, 467-82 (1 pi.). 



