412 SUMMARY OF CURRENT RESEARCHES RELATING TO 



BOTANY. 



GENERAL, 



Including the Anatomy and Physiology of Seed Plants. 



Cytology, 

 Including: Cell-contents. 



" Mitochondrias " of Sexual Cells.*— A. G-uilliermond contributes a 

 note upon the presence of mitochondrias in the sexual organs of plants. 

 The investigations deal with the ovary of different species of Lilium, 

 Canna, Tulipa and Amaryllis, and the anthers of the gourd and Ery- 

 thrina, and show that mitochondrias are always found in the sexual 

 organs of plants. It would thus appear that they are transmitted from 

 the parent to the offspring, and upon germination are differentiated 

 either into leucoplasts, amyloplasts, or chloroplasts, while the ultimate 

 fate of many of them is still unknown. They seem to be identical with 

 the primitive bodies described by Meyer and Schimper, but have much 

 rnore extensive functions than was at first supposed. By analogy with 

 similar structures in animals, we may regard them as cytoplasmic bodies 

 which give rise to the greater part of the products of secretion and 

 differentiation of the cell. 



Structure and Development. 

 Vegetative. 



Comparative Anatomy of the LilioidesB.t— H. Fuchsig has studied 

 the comparative anatomy of the LiHoidege and finds that they naturally 

 fall into two groups, viz. (1) Eugler's group of the Scillete, which bears 

 raphides in the leaves, stem and roots, and (2) the Tulipeje, which are 

 devoid of them. This character is very constant and is accompanied by 

 differences in the anatomic structure. In the leaves and stem of the 

 Scilleaj the ordinary epidermal cells are usually small, unarched and with- 

 out papillfe or hairs, while the radial cell-walls are straight. In the 

 Tulipeffi the epidermal cells are strongly arched and often produced 

 into papillae or hairs, while the radial cell-walls are waved. In the 

 Scille^e tlie assimilatory leaf-tissue consists chiefly of paUsade-cells, but 

 in the Tulipeaj the cells have their long axes parallel with the upper 

 surface. In the stem of the Tulipete there is nearly always a ring of 

 mechanical tissue either embedding or surrounding the vascular bundles, 

 which are without a protecting sheath ; this ring is usually absent in the 

 Scilleas, and when it is present the vascular bundles, with their pro- 

 tecting sheath, are arranged on both sides of it. The roots of all the 

 Tulipea^ (except Fritillaria) have a sheath, which is absent in many of 

 the Scilleae. The latter group has schizogenous spaces in the tissues of 



* Comptes Rendus, cliv. (1912) pp. 888-891. 



t SB. Akad. Wiss. Wien, cxx. 7 (1911) i^p. 957-1000 (3 pis. and 3 figs.). 



r 



