350 THE: JOURNAL OF BOTANY 



My 



Mygalurus 



that this is a mere synonym, unknown, we think, in British books. 

 Under " customary names " we have, to take only two consecu- 

 tive examples, "Asperella" for Leersia and " Andes Grass" for 

 Arrhenatherum: where, one wonders, can such names be " cus- 

 tomary " ? — the text does not explain. 



When we come to consider the botany of the book, we find 

 that "The Order and its Tribes," "The Tribes and their Genera" 

 and "The Genera and their Species," form three chapters, and 

 that the last is "arranged alphabetically for ease in reference" ! 

 The first of these begins : " The grasses have a botanical order to 

 themselves, Gramineae, which is one of two orders — Cyperaceae 

 being the other — forming the Glumiflorge, the most important and 

 most widely distributed group — cohort or series, or whatever it 

 may be called — into which the monocotyledonous plants have 

 been divided/' This, with a sentence from the preface — " For its 

 food plants no botanical order is of greater interest, nor lias any 

 been more written about, some of the books being really wonderful 

 for the labour they involved " — and this on Avena fataa (p. 78) 

 11 This plant affords a noteworthy instance of the limitations of 

 popular metaphor. Sowing wild oats is a phrase that does not 

 appeal to the botanist, for wild oats are very beautiful, and from 

 the wild oats by persistent collection and sowing came the edible 

 and profitable species, A. saliva, the food of horses and men" 

 will sufficiently illustrate Mr. Gordon's style. As to his facts, 

 take this on Gynomrm echviatus — " This species, which is fairly 

 common on the Sandwich meadows, is most useful to the farmer 

 when it dies to prepare the soil for a better grass " (p. 91) — and 

 compare with the statement as to the plant in the Flora of Kent, 

 whence it appears that Hudson's record (1778) has not been 

 confirmed. 



A word must be said as to the plates ; these, although crudely 

 coloured and not well drawn, form the best part of the book, and 

 may be useful to the beginner who wishes to be spared the trouble 

 of working out his plants. 



Die Pitrpiirbakterien. Dr. Hans Molisch. Jena: Gustav Fischer, 



1907. Pp. vii. and 92. Four plates. Price 5 marks. 



Thk author of this treatise has conducted a series of researches 

 on a very interesting group of colour bacteria and now publishes 

 his results. The group differs from other bacteria, in that light 

 and indeed strong sunlight is required for their development. 

 They occur on decaying organic substances where there is a lack 

 of oxygen, as for instance on hay, cooked eggs, bones, worms, etc. 

 If any one of these substances is put in a closed jar well covered 



due 



rple 



month, more or less. Experiments w r ere made with many different 

 culture media, and an entirely new group of these organisms that 

 does not lay down sulphur was discovered and diagnosed. 



