Page:The Journal of Indian Botany.djvu/176

146 THE JOUKNAL OF INDIAN BOTANY. Howard, A., and Howard, G. L. C. The Spike disease of Peach Trees. An example of unbalanced sap-circulation. Indian Forester, Vol. XLV {1919) 611.

The paper describes the pathological condition -of the peach tree which closely resembles the spike of sandalwood. Morphological differences between normal and spiked plants are to be seen in the foliage, the stems, and the roots. Interesting results were obtained by microscopic examination of affected plants at all stages. The leaves show the presence of starch greatly in excess of the< normal, twigs and branches contain " an enormous accumulation of starch in the pith, in the medullary rays in the wood and bast parenchyma and there is a sharp line of demarcation, as regards starch deposition, at the junction of the stock and scion." The chemical composition of the leaves show marked differences. The authors are of opinion that the cause of the spiked condition is to be found in the junction between the stock and the scion, the trouble, arising from the prolonged unbalanced sub- circulation resulting from an imperfect junction of the stock and scion. They think that " the problem would appear to be considerably clarified if the sandal is looked upon as a root grafted on to its hosts, by means of the haustoria and if the association is regarded as symbiotic rather than parasitic." The fact of the transmission of disease by means of grafling and budding would seem to receive a new proof by the hypothesis suggested by the

authors.

E. B.

Reinking lOtto A. Phytopbthora Faberi Maubl : the cause of Coconut bud-rot in the Philipines. Philipine Journal of Science XIV 1919, pp. 130—150.

The first authentic and reliable investigations into this disease in the Phillipines were made in 1908, and it was reported to have been prevalent and serious in one place for ten years previously. The diseased parts are always found to be infected with bacteria, "especially B. Coli, but this is considered as due only to secondary infection. Exactly similarly diseased spots were produced by inoculating young coconut buds with Phytophora faberi obtained from the black rot of Cacao pods. The two diseases are therefore considered to be due to one and the same fungus. The same species is also believed by the author on the evidence of infection-results to be the cause of cancer of seedlings of Hevea rubber, of the rot of Papaya fruits. The author points out the importance of this. No measurements or other identification marks are given.

Since it is difficult to imagine the fungus of the Coconut bud rot in the Philipines to be different from that of India, the author's identification is contrary to Butlers. But it must be remembered that the difference between the genus Phptophthora and Pythium is very small— the latter has sexual spores the former has not — and the more we learn about fungi the more we find, how polymorphic they may be on different hosts.

T- P. F. F.