ZOOLOGY A.ND BOTANY, MICROSCOPY, ETC. 331 



leaves in a rosette ; a second type similar to the first but less pronounced 

 and accompanied by bulbils or runners with scale-leaves and adventitious 

 roots ; the third type, resembling that of Sempervivum, has a vertical 

 stem and a rosette of foliage-leaves : it dies away entirely after flowering, 

 and growth is continued by lateral shoots ; the fourth type is a " many- 

 headed rhizome," the primary root of which lives a long time ; the fifth 

 type is that of the creeping-herb with prostrate shoots and elongated 

 internodes. The leaves of the vegetative shoots are true foliage-leaves ; 

 scale leaves only occur in connection with bulbils and runners. The 

 flowers are fully developed in the year previous to that in which they 

 open, but both pollen and ovules are immature until the year of opening. 

 Staminate flowers are rare, but pistillate flowers are common, being usually 

 terminal and smaller than the hermaphrodite flowers. The terminal flowers 

 also vary somewhat in their number of parts, being sometimes hexamerous 

 and pentamerous. Pollination is usually performed by insects. Pro- 

 tandry is common, but is not to be regarded as a generic character. 

 Protogyny occurs in some cases. Self-pollination is common, and the 

 staminal movements are the same as are usually found in the Saxifragacese. 

 Fruit-setting and seed-formation are common except in those plants 

 which have bulbils or other methods of vegetative propagation. 



Histology of Giant and Ordinary Primula sinensis.* — K. P. 

 Gregory contributes a note upon Primula sinensis, in which he gives 

 the results of numerous observations mostly bearing upon the histology 

 of the two forms. The seeds of the giant varieties are usually larger 

 and flatter than those of the ordinary form. Microscopic examination 

 of various epithelial layers, e.g. those of the young stigma, also of the 

 nuclei of the pollen-mother-cells, shows that the two forms have the 

 same number and form of chromosomes, but that there is a difference 

 in size. There is a corresponding difference in the size of the resting 

 nuclei and in the cells. 



Classification of the Aloes by Leaf-structure. f — F. Lange pub- 

 lishes an account of a long series of observations upon the leaf -structure 

 of the aloes. The author has studied the genera Aloe, Gasteria, 

 Haworthia, Apicra, and Lomatophyllum, and is of the opinion that they 

 may be classified by means of the anatomical structure of the leaf, and 

 publishes a scheme whereby the relationship of the above genera is 

 clearly shown. The limits of the present classification do not always 

 correspond with those of existing classification, but close examination 

 shows that the differences are immaterial. The structures that form the 

 basis of the present system of arrangement are the general external 

 form of the leaf, the formation of the epidermis, more especially of the 

 cuticle, the structure of the vascular bundles, and, lastly, the nature of 

 the crystals accompanying the raphides. 



Reproductive. 



Embryology of Encephalartos.J— W. T. Saxton has studied the 

 development of the embryo of Encephalartos, and shows that the sus- 



* Proc. Camb. Philos. Soc, xv. 3 (1909) pp. 239-46. 

 t Bot. Zeit., lxviii. (1910) pp. 1-47 (33 figs.), 

 t Bot. Gaz., xlix. (1910) pp. 13-18, 1 pi. (1 fig.). 



