60 SUMMARY OF CURRENT RESEARCHES RELATING TO 



BOTANY. 



GENERAL, 



Including the Anatomy and Physiology of Seed Plants. 



Cytology, 

 including- Cell-Contents. 



Aleurone Grains.* — J. Beauverie has studied aleurone grains with 

 special reference to the nitrogenous substratum of the mineral salts of 

 the globoids. The author has proved that the substance of the globoids 

 can exist apart from aleurone grains in the integuments and other 

 tissues of maturating seeds, and in some cases he has found granules of 

 the same substance in the cytoplasm and between the cells. The experi- 

 ments seem to show that these granules are of the same nature as the 

 metachromatic corpuscles found in the lower animals, and belong to the 

 class of substances known as volutins, which are akin to fats, hydro- 

 carbons, etc., but contain nitrogen and phosphorus in addition to carbon, 

 hydrogen, and oxygen. Thus it would appear that the present work 

 confirms the hypothesis which regards the nitrogenous substance of 

 globoids as reserve food-materials. 



Structure and Development. 

 Vegetative. 



Seedling- of Ceratozamia.t — H. A. Dorety has studied the seedling 

 anatomy of Ceratozamia, and her conclusions are as. follows. Ceratozamia 

 has two cotyledons, one of which aborts. The persisting cotyledon has 

 many bundles, and is often lobed at the apex. Mesarch wood is found in 

 the lower portion, and exarch wood in the upper part. Mucilage-ducts 

 are often found between the bundles. The wood of the leaf-traces is 

 endarch in the central cylinder, but is mesarch from the leaf-base out- 

 wards. The primary portion of the vascular cylinder may be a protostele. 

 Several layers of extrafascicular cambium are present, but in two years 

 there is only a very slight trace of anomalous thickening. The root, 

 which is of late development, has a complete ring of cambium around 

 its xylem. 



Secretory System of Ginkgo.:!: — A. Sprecher has examined the root, 

 stem, petiole, leaves, bracts and floral axes of Ginkgo in order to investi- 

 gate the origin of the secretory system. The root has no secretory cells, 

 but the author finds secretory sacs in the pith and primary cortex of the 

 stem and petioles, and also in the leaves and older female floral axes. 

 The largest sacs are developed in the bases of the young ovules and 

 stamens. There are no secretory canals such as occur in other Conifers, 

 but the whole system appears to resemble that of the MarattiaceaB in its 



* Ann. Sci. Nat., ser. 9, viii. (190S) pp. 147-75 (2 pis.), 

 t Bot. Gaz., xlvi. (1908) pp. 203-20 (5 pis. and 2 figs.). 

 % Beih. Bot. Centralbl., xxiv. (1908) pp. 63-82 (2 pis. and 19 figs.). 



