248 BOTANICAL GAZETTE [h^ch 



by ingenuity in devising efficient apparatus and illustrates the potency of logical 



inquiry 



is not given. 



Egypt 



■ganism 



noted that cultures of this "sore-shin" fungus showed a notable difference between 



thermal 



observatioi 



suggested an analysis of the temperature factor in its effects upon growth. It is 



fungus are morphologically and physiologically 



formation 



course 



this statement is not to be taken literally, as it would be very difficult to say that 

 all the hyphae of a given fungus are physiologically equivalent. As a matter of 

 fact, the author himself states that in liquid cultures at 20 C. resting cells ait 



formed 



If the cultures are grown at 34 C. growth ceases (culture 

 becomes stale) much earlier than at lower temperatures. This feature of "stale- 

 ness" or of discontinued growth was found to be caused by the accumulation of 

 substances which retard and if sufficiently concentrated stop growth. The sub- 

 stance or substances which originate in the organism as a result of the effect oi 

 temperature, and whose influence is to inhibit growth, have been isolated from 



chemically 



identified. To such katabolites the provisional name of "X" is given. From 



appropnate 

 increas- 



n io° C 



and this acceleration approximately fulfils the expectation based upon 1W 

 Hoff's law; (b) above 3 o° C. the growth-rate acceleration decreases as the factor 

 of time becomes limiting; (c) later growth stops at a fairly definite temperature, 



(i) the optimum is there 

 v effects 



— - .^ a. ucuime temperature but a status ot the organism in w«n- ■— — 

 of the factors of time and of temperature physiologically balance. As would he 

 expected the style and composition of the paper are consistent with the logical 

 development of the investigation.— Raymond H. Pond. 



Seedlings of conifers.— With the hope of finding facts of phylogenetic imp*" 



, Fraine began, some time ago, a comparative study of the tra 



tion region in seedlings. Their preliminary announcement of results was no 

 in this journal;" the first paper of the series has appeared recently- " 



The species examined in this part of the work are included in thirteen gen 

 of the Coniferales. Two subfamilies of the Taxaceae are represented, the V 

 carpmeae and the Taxineae; and of the Pinaceae two subfamilies, the Tawd* 

 and the Cupressineae. In all the conifer seedlings examined the authors 

 the transition to be according to van Tieghem's type 3 or a modification 

 In all but Podocarpus, which has two, there is only one vascular bundle 1 



"Bot. Gazette 43: 77 . I0o7 . 



Hill 



■mnosperms. I 



Annals of Botany 2 2 : 689-7 12. 1 908. 



