n 



September i6, 19 15] 



NATURE 



77 



by M. A. I. Lobik in the Bulletin of the Imperial 

 Botanic Garden of Peter the Great, vol. xv., No. i, 

 1915. Sixty-five species are enumerated; they include 

 one Floridean alga, Batrachospermum moniliforme, 

 one brown alga, Hydrurus foetidus, twenty-five Chloro- 

 phyceas, twenty-four diatoms, and fourteen members 

 of the Cyanophyceae. Among the Chlorophyceae a new 

 form of Spirogyra and of Cosmarium are described, and 

 also a new genus, Leptobasis, among the C/ano- 

 phyceae. This new alga, L. caucasica, forms the sub- 

 ject of a separate memoir by M. A. A. Elenkin, who, 

 with M. V. P. Savicz, made the whole collection, 

 Elenkin, in determining the new genus, revises the 

 old genus Michrochaete, and considers that the genera 

 Michrochaete, Coleospermum, and Leptobasis should 

 be classed in different sections of the Hormogonese. 

 The paper is illustrated with text figures. 



In the Philippine Journal of Science for May (vol. x., 

 So. 3), Mr. E. D. Merrills contributes four papers 

 dealing with Philippine botany, and describes a num- 

 ber of new species of the genera Schefflera and 

 Eugenia. In the opening paper on the present status 

 of botanical exploration in the Philippines, which is 

 illustrated by a map of the group, Mr. Merrill gives 

 interesting particulars showing the amount of work 

 which has been accomplished during the past thirteen 

 years, and the parts of the archiiselago which have 

 been thoroughly explored. Compared with Java, 

 Singapore, and Penang, the flora is not well known, 

 and though much work has been done it has been 

 confined to a few definite areas in Luzon and Min- 

 danao. The islands are so densely forested that even 

 in those regions visited by botanists on short excur- 

 sions jonly a tithe of the plants has probably been col- 

 lected, and a large number of endemic forms doubt- 

 less await discovery. Some fifteen years ago 2500 

 species of flowering plants were recorded from the 

 islands ; now the number is estimated at rather more 

 than 7000, and it seems probable that 10,000 species is 

 not an extravagant estimate for the phanerogamic 

 flora of the Philippines. Some 40 per cent, of the 

 whole Malay Archipelago flora will probably be found 

 to be endemic in the islands. 



Tare-like rogues appear from time to time among 

 culinary peas, and are characterised by the possession 

 of stipules and leaves narrower and more pointed than 

 those of normal plants. The pods also are distinct, 

 since they are always curved and narrow, even though 

 the races in which the rogues have arisen bear straight 

 pods, and the seeds are less sweet than those of the 

 types. The seed-raiser has attempted to eliminate the 

 rogues by destroying them as they appear, but all to no 

 purpose ; the rogue still reappears, and with the object 

 of understanding its origin and finding a means of 

 control, Mr. Bateson and Miss Pellew have conducted 

 a series of investigations at Merton, and have pub- 

 lished their results in the Journal of Genetics (vol. v,, 

 No. i) for July. Though the research has been ex- 

 tended and a large series of plants examined, the 

 origin of the rogue is still a mystery, nor has a 

 method been devised as yet for the elimination of these 

 tare-like plants. Rogues may depart widely or only 

 slightly from the type; in the latter case rogue char- 

 NO. 2394, VOL. 96] 



acters may only appear in the youngest parts, but as 

 such plants can produce complete rogues among their 

 offspring they should be weeded out. Rogues in breed- 

 ing beget only rogues, and even in a strain of quite 

 normal plants rogues occasionally appear. One re- 

 markable result of the inquiry is that normal plants 

 crossed with rogues always give rogues, and this was 

 found to be true in fifty out of fifty-two crosses, and 

 to persist through three generations. 



The methods of bacterial analysis of air have recently 

 been investigated by Mr, G. L. Ruehle in the course 

 of an inquiry into the contamination of the air of 

 cowsheds and its eft'ects on the milk supply. In 

 vol. iv., No. 2, of the Journal of Agricultural Research, 

 a large number of comparative analyses is described 

 in detail. Three forms of apparatus were used : (i) the 

 standard sand-filter aeroscope of the American Public 

 Health Association ; (2) a modification of the standard 

 designed by the author to permit sterilisation by dry 

 heat; and (3) the Rettger liquid-filter aeroscope.^ The 

 efficiency of the aeroscopes was tested by running two 

 of each type in tandem so that the air passes through 

 one filter and then through the other. The percentage 

 of the total number of bacteria caught by the first 

 filter determines the efficiency. The standard aero- 

 scope was found to have a very variable efficiency, 

 averaging 90 per cent., but the modified standard 

 retained nearly 100 per cent, of the bacteria. The 

 Rettger apparatus also gave excellent results, but 

 required greater care in manipulation, as difficulties 

 occur with foaming of the liquid during filtration and 

 the tenacity with which the bacteria cling to the inner 

 surface of the moist inlet tube. The method of deter- 

 mining bacterial precipitation from air by exposing 

 Petri dishes is quite untrustworthy, as it only measures 

 the number of bacteria-laden dust particles falling on 

 the plate. The exposure of sterile water in pails gives 

 an average bacterial count ten times higher than that 

 obtained by the plate method. 



We have received vol, xxvi. of the Anales of the 

 National Museum of Natural History of Buenos 

 Aires, containing a useful index to the first twenty 

 volumes of this publication (1864-1911), and an in- 

 teresting illustrated account of the fine new building 

 for the museum which it is hoped will soon be pro- 

 vided by the Argentine Government. Under the 

 energetic direction of Dr, Angel Gallardo, the tech- 

 nical scientific work of the museum has become very 

 varied, and the newly-published volume contains 

 several valuable contributions to systematic zoology 

 and botany. There is also an exhaustive study of the 

 collection of human skulls from Patagonia, with 

 numerous tables of measurements. The most gener- 

 ally interesting research is a new examination of the 

 deposits on the coast of the province of Buenos Aires 

 containing human remains or implements made by 

 man. This has been instigated by the criticisms of 

 Argentine discoveries published by Drs. HrdliCka, 

 Holmes, and Willis in their work on " Early Man in 

 South America " (Smithsonian Institution, 1912). It 

 is maintained that in the neighbourhood of Mar del 

 Plata and Miramar there is no reason to doubt the 

 association of evidence of man with late Tertlarv 



