i6o 



NATURE 



[April 20, 19 16 



able us to foretell some of the course of human 

 behaviour. The war brings the chance of testing- 

 the truth of this suggestion. It is becoming, 

 obviously, more and more a war of moral forces ; 

 and an understanding of the nature and sources 

 of national moral must be as important a source 

 of strength as the knowledge of the military 

 engineer. 



The author proceeds to discuss the various 

 forms of gregariousness, and finds the British form 

 typified by the bee, the German form by the wolf. 

 The difference is so great that the war is not so 

 much a war between nations as a war between 

 different species. Nature is making one of her 

 great experiments; is setting herself to try out 

 the strength of the socialised and the aggressive 

 types. To the socialised peoples she has entrusted 

 the task of proving that her old faith in cruelty 

 and blood is at last an anachronism. To try 

 them, she has given substance to the creation of 

 a nightmare, and they must destroy this werewolf 

 or die. And a calm consideration of the German 

 and the British mind leaves us in no doubt where 

 the strength lies. In Britain there has been no 

 Hymn of Hate, no "God punish Germany! ", no 

 gospel of bluster and frightfulness. These are 

 symptoms of lupine rage. But Britain, fighting 

 for existence and for honour, has quieter and 

 deeper vision ; and she will not sheathe the sword 

 until her task is done, and a peaceful Europe 

 once more possible, freed from the terror of im- 

 minent wanton attack by an aggressive Power. 



British Fungi and How to Identify Them. By 

 J. H. Crabtree. Pp. 62. (London: C. H. 

 Kelly, n.d.) Price i5. net. 



Our native fungi afford beautiful objects for the 

 photographer, and have been well illustrated in 

 the many popular and scientific works v/hich deal 

 with them. In the little book before us Mr. Crab- 

 tree illustrates some forty different species of well- 

 known fungi by means of very good photographs, 

 and each photograph is accompanied by a page 

 of useful descriptive text. By the aid of both text 

 and illustration a particular fungus should be able 

 to be identified without much difficulty. In the 

 case of the somewhat small differences between 

 certain edible and poisonous fungi the ordinary 

 photographic reproduction is not sufficiently clear 

 to show the distinguishing features, and a few 

 good colour prints would have been of value. 



In a short introduction of four pages the author 

 gives a concise account of the larger fungi in 

 general — with which only this little book is con- 

 cerned — details as to the spore-arrangement, etc., 

 and a simple classification. It is unfortunate 

 that Mr. Crabtree's frontispiece, "An unnamed 

 fungoid growth found upon a tree," is not a 

 fungus at all, but is what is known as a "wood 

 flower." This hollow woody grow-th has been 

 gradually formed about the suctorial portion of 

 some parasitic plant, probably a Loranthus, which 

 has become detached and has left a large tulip- 

 shaped woody scar resembling a fungus on the 

 branch of its host plant. 



NO. 2425, VOL. 97] 



LETTERS TO THE EDITOR. 



[The Editor does not hold himself responsible fut 

 opinions expressed by his correspondents. Neilhei 

 can he undertake to return, or to correspond viiih 

 the writers of, rejected manuscripts intended fot 

 this or any other part of Nature. No notice ii 

 taken of anonymous communications.] 



The Primary Sugar of Photosynthesis. 



MiCROCHEMiCAL tests OH the assimilating cells ol 

 several plants indicate a considerable concentralior 

 of hexoses in the chloroplasts, or in the protoplasm 

 immediately surrounding them. Other lines of ex- 

 periment suggest that while sucrose is concentrated in 

 the large vacuoles, invertase is held apart from it in 

 the protoplasm. 



These facts force upon one the possibility that tht 

 pioneer analytical work of Brown and Morris estab- 

 lished and extended by Parkin and by Davis and his 

 collaborators, does not after all necessitate the con- 

 clusion that the formation of sucrose is a preliminar) 

 step to the production of hexoses in the leaf. 



It seems more probable that the hexoses are formed 

 from formaldehyde in the chloroplast, and, when their 

 concentration reaches a certain limit, condensation 

 into sucrose due to invertase, or some saccharogenic 

 enzyme, takes place. The sucrose thus formed is 

 passed into, and stored in the vacuole. As the volume 

 of the protoplasm available for the hexoses is small 

 compared to the space allotted to the sucrose, the in- 

 crease of the total percentage of hexoses will be small 

 when the leaf is exposed to light, while that of tht 

 sucrose will be large. Consequently the rise of sucrose 

 on illumination shown in analyses of leaves is not a 

 cogent argument for regarding it as the primary 

 sugar. 



The recognition of the localisation of various sub 

 stances in the cell also supplies an explanation as tc 

 how the sucrose-hexose ratio of the cell is maintainec 

 in presence of invertase. The absence of invertasr 

 from, and the storage of sucrose in the vacuole m 

 be compared to the conditions obtaining in the ro 

 of the sugar beet. Only there, of course, the sour 

 of sucrose is secondary hexoses. In photosynthe- 

 the condensation of the sugars is probably determin' 

 by the fact that for the same rise of osmotic pressi: 

 in the vacuole twice the amount of the disacchari 

 may be stored. When the limiting pressure is reach 

 in this way the condensation of hexoses to starch m 

 give extended elasticity to the economy of the cell. 



Henry H. Dixox. 

 Thomas G. Masox. 



School of Botany, Trinity College, Dublin, 

 Aoril 10. 



isle of Wight Disease in Bees. 



Drastic recommendations regarding the disinfecti< 

 or destruction of combs, hives, and appliances whi' 

 have come in contact with bees infected by Isle 

 Wight disease have been made by the Board of Agi 

 culture, and were repeated in an article in Nature 

 March 2 (p. 7). The recommendations are found 

 upon the idea of the infectiousness of the disease, ai 

 are intimately connected with the recognition of t 

 protozoon Nosema apis as the cause of the diseas 

 and with the knowledge of the ease by which tl 

 parasite can be disseminated by infected bees, t 

 account of the practical importance of the subject, 

 would direct attention to the results of experimer 

 bearing upon these points, carried out by Mr. 

 Anderson and Dr. J. Rennie, of the North of Scotia i 

 College of Agriculture and University of Aberdf 

 respectively, and communicated at a recent meeti 



