'25S SUMMARY OF CURRENT RESEARCHES RELATING TO 



tho coll of the alga in which it is found. Sphserita endogena at no stago 

 of its existence introduces solid particles in its protoplasm. Wo are in 

 this case, then, easily able to distinguish the one from, tho other; tho 

 former being an animal, and tbc Litter a vegetable. 



The author concludes by stating that the Chytridinero and Chlamy- 

 domonadineee are two primary groups of tho vegctablo kingdom; tho 

 one being related to tho alga3, tho other to the fungi. Their mode of 

 nutrition alono allows of their vegctablo nature being recognized. 



Growth of the Leaf-stalk.* — Herr P. G. Uhlitzsch compares tho 

 mode of growth of the leaf-stalk with that of other axial organs, and 

 finds that it is governed by the sarao general laws. On tho boundary of 

 the leaf-stalk and lamina there is usually a growing-point, from which 

 proceeds the activity of growth of tho organ. 



Modes of Climbing in the genus Calamus.f— Prof. F. O. Bower 

 states that it is of the greatest importance to climbing plants that the 

 assimilating leaves should be exposed to the sunlight; and this they 

 strivo to effect by a straggling habit, and by the help of adaptation for 

 mechanical support on other plants. If, in the case of Calamus, the 

 axillary bud were developed as a flagellum, but remained inserted in 

 the axil of the next lower leaf, the two members, being extended in tho 

 same plane and the leaf being the lower, it is improbable that the lower 

 portion of the flagellum would come in contact with any support. But 

 the case is otherwise when the axillary bud is displaced and adherent to 

 the sheath of the next higher leaf ; it is thus clear of its own subtending 

 leaf, and projects freely from the shoot at a point considerably above it. 

 This being so, it is probable that, as the plant straggles through and 

 over the surrounding vegetation, even the lower parts of the flagellum 

 will have an opportunity of affording support to the whole shoot. 



The two sections of the genus Calamus show two very distinct types 

 of adaptation of the shoot to meet the exigencies of a climbing habit : 

 the one developes the apex of the leaf, the other the axillary bud of the 

 flagellum. Thus we see how plastic is the vegetative shoot in its mode 

 of development within a single genus. 



Assimilation and Respiration of Plants. J — Herr U. Kreusler, in 

 this continuation of former experiments, § gives the details of experi- 

 ments made with the shoots of the same kind of plant, Philadelplius 

 grandiflorus, at different stages of growth, the temperatures of observa- 

 tion being 15° and 25°. At a temperature of 25°, a strong and marked 

 decrease in assimilative power accompanies increasing age of the leaf ; 

 at 15° a maximum of assimilative power is noticed in the youngest 

 leaves. This power reaches its minimum at the period of blossom, and 

 rises again in the oldest leaves ; so that between the assimilative power 

 in the youngest and in the oldest leaves there does not exist much dif- 

 ference. A table showing the amount of water absorbed at the different 

 temperatures is also given. 



In the second portion of this paper, amongst many statements con- 

 cerning the absorption and exhalation of carbonic anhydride at different 



* Uhlitzsch, P. G., ' Unters. iib. d. Wachsthum d. Blattstiele,' 62 pp. and 4 pis., 

 Leipzig, 1887. See Bot. Ceutralbl., xxxii. (1887) p. 263. 



t Ann. of Bot., i. (1887) pp. 125-31. 



% Journ. Chem. Soc. Lond., 1SS8, Abstr., pp. 186-7, from Bied. Centr., 18S7, 

 pp. 669-81. § Of. Bied. Centr., 1887, p. 110. 



