June 14, 1906] 



NA JURE 



157 



state of affairs is shown to exist in the case of Volutilithes, 

 with the important exception that the main ancestral line 

 is the one which is dominant. 



The Ostracoda of the San Diego region (No. i), the 

 California shore-anemone, Bunodactis xantlwgtanima, and 

 sexual dimorphism in the hydroid polyps of the genus 

 Aglaophenia, form the subjects of articles nine, ten, and 

 eleven of Contributions from the San Diego Marine Labor- 

 atory issued in vol. iii. of the Zoological Publications of 

 the L'niversity of California. In the article on dimorphism 

 (by Mr. H. B. Torrey and Miss Martin) it is shown that 

 in the genus mentioned, not only are the gonophores 

 dimorphic, but an analogous dissimilarity also obtains in 

 the jointed plumose structures known as corbula;, of 

 which numerous examples are figured. The plate intended 

 to illustrate Mr. Torrey's paper on the sea-anemone was 

 destroyed in the San Francisco fire, but a new one will 

 be supplied later. 



The April issue of Spolia Zeylanica is of more than 

 usual interest. It opens with a translation of an article 

 by Dr. F. Dofiein, of Munich, entitled "Termite Truffles," 

 being the description of certain remarkably nodular masses 

 of fungus cultivated in their nests by white ants in Ceylon. 

 The hillocks of these termites were found by the author 

 to contain a number of large chambers, each approximately 

 the size of a cocoanut, and each containing one or more 

 large friable masses, looking somewhat like small bath- 

 sponges. These cakes were occupied by thousands of 

 termites, ensconced in the cells and connecting passages. 

 The framework of each was beset with numerous while 

 nodules of the size of pins' heads, which proved to be 

 fungus-growths. These nodules are eaten by the larvae of 

 the workers and soldiers and by the sexual forms at all 

 ages, the adult soldiers and workers having, however, 

 other food. That the funguses are introduced and culti- 

 vated by the termites seems undoubted. In the same 

 publication Dr. A. Willey records a singular instance of 

 symbiosis in a crab, originally described from Mauritius 

 under the name of Melia tessellata. When first described 

 its habit of holding sea-anemones in its two front claws 

 was not noticed, but although this was observed later on 

 in Mauritius, it has been generally overlooked. According 

 to Dr. Willey 's account and figure, the crab holds in each 

 claw a small white anemone, which it presents, wilh the 

 tentacles fully expanded, to every intruder, in " true boxing 

 attitude." The ground-colour of the crab is whitish with 

 a rosy flush on the front of the shell, which has also a 

 pattern of black lines. " Probably both crab and actinians 

 benefit by the association, the actinians enjoying increased 

 mobility, and the crab sheltering and defending itself with 

 the living gloves with which it is provided." In the 

 author's opinion, the stinging threads of the anemone are 

 the active means of defence and offence. 



A LEAFLET, No. i6, published by the Department of 

 Agriculture in British East Africa, contains the reports on 

 various samples of cotton grown at Golbanti and Malindi. 

 The cotton was produced from Egyptian Afifi seed, except 

 for one sample of Sea Island and one of American upland. 

 The soils on which the crops were grown were a heavy 

 alluvium or a lighter red soil, the latter yielding much 

 better results, owing probably to its requiring less cultiva- 

 tion. The values, except for the Sea Island, ranged between 

 fivepence and si.\pence per pound. There is a striking 

 difference between the yield from Egyptian seed on the red 

 soil and the other crops obtained. 

 NO. I9II, VOL. 74] 



The green colour of plants is such an ever-present reality 

 that the explanation is apt to be overlooked. The absorp- 

 tion spectra of chlorophyll and the curves of absorption 

 and assimilation do not directly furnish a solution, and it 

 is only from the consideration of these, together with the 

 effects produced by the absorption and dispersion of light 

 rays in the atmosphere, that a satisfactory explanation is 

 obtained. The subject is ably discussed by Prof. E. Stahl 

 in Naturwissenschaftliche Wochenschrift for May 6, where 

 he points out that the two pigments contained in chloro- 

 phyll are suited to the sun's rays as modified by reflection, 

 the colours being complementary to those of the chloro- 

 phyll-absorbing rays that predominate in diffused light, 

 and that certain rays, e.g. the ultra-red, are excluded 

 wholly or in part owing to the danger of too great absorp- 

 tion in direct sunlight. 



The fungus Phycomyccs nitens is well adapted to physio- 

 logical investigation owing to the rapidity of its growth 

 and its sensibility to stimuli. Proceeding out of investi- 

 gations by Elfving wherein curvature of the sporangio- 



FlG. I. — Phyconty 



mutated to gri 

 rface of a porous pot. 



phores was attributed to physiological action through space. 

 Prof. L. Errera was led to experiment on the curvatures 

 caused by the presence of various substances such as rough 

 and polished metals, porcelain, glass, deliquescent salts, 

 marble, mica, &c. The results so obtained, and the notes 

 relative to them, had been sufficiently fully drafted before 

 Prof. Errera's death to allow of publication, and they 

 appear in Recueil de I'Institut botanique, Brussels, vol. vi., 

 1905. It was found that Phycomyces curves towards bodies 

 that absorb moisture and away from those that give off 

 vapour. Thus the sporophores curve towards an unpolished 

 rod of iron, but not towards a piece that is perfectly 

 polished. A number of photographs accompany the paper, 

 of which one of the most striking is reproduced. A dry, 

 porous pot is suspended over the Phycomyces growing on 

 bread in a moist atmosphere. The pot absorbs moisture, 

 and the sporophores have curved right over the surface of 

 the pot, some of them ultimately turning upwards owing 

 to the stimulus of gravity. 



