Page:The Journal of Indian Botany.djvu/86

64 THE JOURNAL OF INDIAN BOTANY. Variegated plants though not of these genera are so commonly grown in our Indian gardens and are so easily propagated, that it seems worth while suggesting an examination of the plants in gardens, for other instances of reversal. Interesting' problems of heredity are bound up with the inheri- tance of these chimaeras. P. F. F.

Bristol, B. M., Miss., On a Malay form of Chlorococcum humicola (Nag) Rahenbh. Jour. Linn. Soc. Bot. XLIV, No. 299, {July, 1919) pp. 473—480, pi.

A specimen of soil from Kajang, Malay States, which had been air-dried and stored for two years, was put in a suitable culture-fluid, and after some eight months an alga was found which soon developed quite healthily and proved to be in no way different from the English Chlrococcum humicola.

Germination was certainly slower, and the cells larger, but the author points out that the size varies in the cultures a very great deal, cells being measured from 20 to 80 in diameter. The formation of both zoogonidia and of aplanospores was observed, and in the former an abnormal form seen where owing to the liberation of the zoogonidia before the division had been complet- ed, a triangular body appeared with pairs of cilia at the three corners. The author explains the parmella stage which follows the formation of aplanos- pores as idicating that the latter are " really reduced zoogonidia, but that the surrounding nutrient conditions are such as to be able to support the develop- ment of a large number of individuals in a small space, and to render their wider distribution unnecessary ", a teleological explanation which seems hardly sufficient to account for the palmella stage. As illustrating the extra- ordinary resistance of the spores to desiccation the author gives her ex- perience with samples of soil which were collected as long ago as 1846, and 1856 from a plot at Rothamstead. From the former she did not obtain any growth, but did from the latter, which shows that the limit of retention of vitality lies between 70 and 80 years.

P. F. F.