350 



NA rURE 



[February 13, 15 



•cntitlud " Tlip Physiognomist at the Zoo," Mr. A. E. 

 Johnson discourses pleasantly on the expression of animals 

 as an indication of character, his points being brought 

 out bv four striking — if somewhat accentuated — portraits 

 of Ihe lynx, the chimpanzi, the mantled guereza monkey, 

 and the loris. The second article, by Mr. D. M. Beddoe, 

 is devoted to the recently discovered mummy believed to 

 be that of Menephtah, the Pharaoh of the Exodus, and 

 the son of the great Rameses. Photographs of the 

 mummy illustrate the article, so that the reader may look 

 ■on features familiar to Moses some three thousand or 

 more years ago. 



In the January number of the Quarterly Journal of 

 Microscopical Science Mr. C. C. Dobcll describes the life- 

 history and development of a newly discovered genus and 

 species of flagellate monad {Copromonas subtilis) inhabit- 

 ing the fa?ces of frogs and toads. Starting with the adult 

 monad, it appears that the organism undergoes two dis- 

 tinct phases or cycles of development, one asexual and the 

 other sexual. In the former multiplication takes place by 

 means of longitudinal division, with the eventual develop- 

 ment of two flagellas and two nucleuses. In the sexual 

 stage the monads conjugate in pairs, and thus eventually 

 give rise to a dormant cyst, from which, when a suitable 

 nidus is reached, a small hyaline monad is liberated, this 

 in due course developing into an adult monad, when the 

 whole cycle recommences. The cysts are swallowed by 

 frogs or toads, and reach the rectum by Ihc usual course. 



The anatomy and histology of the alimentary tract of 

 the dugong are described in detail by Mr. J. F. Guder- 

 natsch in the fourth part of vol. xxxvii. of Gegenbaur's 

 Morphologisches jahrbuch. At the conclusion of the paper 

 the author refers to some curious resemblances between 

 the sirenian and the cetacean tongue. In that organ in 

 th" dolphin there have, for instance, been found certain 

 peculiar pits occupying the position of the circumvallate 

 papillae in other mammals, while the author has discovered 

 very similar pits in the dugong which occupy the position 

 of the foliate papill£e. Whether these pits are connected 

 with the sense of taste is, however, uncertain, although 

 the occurrence in both cases of ganglionic cells in the pits 

 Is in favour of such a function. An important difference 

 between the sirenian and cetacean mouth is the presence 

 in the former of large salivary glands, which are totally 

 wanting in the latter. 



.\ SF.RIES of " Studies :n adaptation " commences in the 

 fifth volume of the Baltimore Journal of Experimental 

 Zoology with an article by Dr. Alexander Petrunkevitch 

 on the sense of sight in spiders, a subject discussed with 

 great elaboration and in minute detail. This sense is of 

 the greatest importance to certain species, those which 

 obtain their prey by hunting depending entirely on sight 

 tUiring the chase. Nevertheless, the acuteness of vision 

 <jvcn in the sharpest-eyed spiders is far inferior to that of 

 man. .\n insect of about a square centimetre in size 

 would, for example, be perfectly visible — even perhaps to 

 the extent of specific recognition — to the human eye at the 

 <listance of a yard, whereas to a spider of the genus 

 Phidippus it would appear as a tiny, ill-defined moving 

 object, while to members of the genus Lycosa it would be 

 invisible. The poor visual power of spiders is largely due 

 to the peculiar form of the retina, while the inferiority 

 in this respect of Lycosa to Phidippus depends on the 

 fact that, while in the latter the retinal image covers the 

 terminations of nearly seven nerve-rods, in the former it 

 scarcely exceeds the diameter of a single rod. 



NO. 1998. VOL. yy'] 



The best mode of determining the age and rate of 

 growth of eels forms the subject of a long article by Mr. 

 K. J. Gemsoe in the report of the Danish Biological 

 Station for 1906 [Copenhagen, 1908). By means of 

 measurements, it has been ascertained that when eels 

 attain a length of about 18 cm. and begin to develop 

 scales, they have lived for two years in fresh water, that 

 is to say, from the time of their arrival as larvae or glass- 

 eels. After this the age may be determined by the number 

 of concentric zones or rings in the scales, which indicate 

 annual periods of growth. The age of any individual eel 

 is therefore the age of the scale +2. Judged by this 

 test, it appears that in the case of males some assume 

 the silvery breeding-dress (preparatory to descending to the 

 ocean) in about 4I years after their arrival in fresh water, 

 although the majority do not do so until from 55 years 

 to 7j years. The females, on the other hand, assume the 

 silver livery somewhat later, scarcely ever before 65 year;-, 

 and in most cases not until 75 years, while many do not 

 do so until they are 8J years old or even more, whereas 

 only one male of that age was detected in the course of 

 the experiments. It is during their fourth and fifth years 

 that eels increase most rapidh- in girth. 



In an article on the evolution of life, published in the 

 Century Illustrated Magazine for February, Dr. Percival 

 Lowell asserts that life is an inevitable phase of planetary 

 evolution, and consequently that every planet must be 

 inhabited by living creatures of some kind during a certain 

 stage of its existence. Mars is at present passing through 

 this stage. The author also considers it demonstrated that 

 in the case of our own planet life originated in the ocean. 

 Very picturesquely does he describe the life of the deep 

 sea. That a blind fauna, he writes, should inhabit the 

 abyssal depths is of itself a sufTiciently wonderful pheno- 

 menon ; but that nature should undertake to light the 

 region, and that by means of its inhabitants, is still more 

 wonderful. And yet " this is precisely what she does, 

 and with something akin to electricity, each animal carry- 

 ing with it its own machine. Whole tracts are brilliaiWV.' 

 lighted up, till they must resemble London or Paris by 

 night, only that in these thoroughfares of the abysses of 

 the sea the passers-by provide the illumination." 



Prof. Dijnbar, as the result of a series of experiments 

 conducted over a long period and with every care, has 

 come to the conclusion that the bacteria are not an in- 

 dependent group of organisms, but, together with some 

 of the yeasts and moulds, are stages in the life-history of 

 green algre (" Die Entstehung von Bakterien, Hefen und 

 Schimmelpilzen aus Algenzellen," published by R. Olden- 

 bourg, Munich and Berlin). A pure culture of a single- 

 celled alga belonging to the Palmellacia was obtained, but 

 by modifying the culture medium by the addition of acid, 

 alkali, or traces of copper salts, other organisms, generally 

 bacteria, occasionally moulds and yeasts, and even spiro- 

 chsetes, made their appearance in the pure cultures. 

 Granting there was no flaw in the experimental methods, 

 and every care seems to have been taken to exclude con- 

 tamination, the results are susceptible of another explana- 

 tion, viz. that the secondary growths were derived by 

 transformation of the algal cells, in fact, by the pheno- 

 menon of " heterogencsis, " which has been claimed by 

 Bastian to occur with certain organisms. 



An editorial in the Indian Forester (November, 1907) 

 on "Forestry and Agriculture," advocating the afforesta- 

 tion of some of the large areas of uncultivated or un- 

 culturable land in India, touches on a matter of great 

 importance, seeing that so much timber is required as fuel. 



