1 902 1 CURRENT LITER A TURE 



457 



NOTES FOR STUDENTS. 



The thirteenth part (Jour. Linn. Soc. 26 : 538-561. 1902) of Forbes 

 and Hemsley's " Enumeration of all the plants known from China proper, 

 Formosa, Hainan, Corea, the Luchu archipelago, and the Islands of Hong- 

 kong " contains the gymnosperms of that very interesting region, the enu- 

 meration being as follows: Gnetales S spp. (Ephedra 4, Gnetum i); Conife- 

 rales 64 spp. (Libocedrus i, Thuja i, Cupressus 2, Juniperus 7, Cryptomeria 

 I, Glyptostrobus i, Cephalotaxus 5, Taxus r, Torreya 2, Podocarpus 6, Cun- 



ninghamia i, Pinus 11 



[ 



Abies 4, Pseudolarix i, Larix 6); Ginkgoales i sp. ; Cycadales 4 spp. (Cvcas). 

 J. M. C. 



The germination of dry seeds after exposure to high temperatures has 

 been studied by Dixon.*^ After being desiccated for a day at e^'' to 75°C, 

 and then for another day at go'^C, the seeds were subjected to the various 

 temperatures for one to two hours, and then planted. In seeds which have 

 been subjected to high temperatures germination is much slower than in the 

 control. Also growth of the seedling is often abnormal in the case of heated 

 seeds. The author believes, on experimental grounds, that the retardation 

 of germination is due to some effect of the \Lt?X per se, and not to more com- 

 plete desiccation. Some maximum temperatures withstood are the follow- 

 ing: A vena saiiva, ir8\' Cuctirbita pepOy 112''; Helianihus anntius, 112°; 

 Lotus tetragonolobiis^ 100""; Convolvulus tricolor^ 120°. These experiments 

 emphasize again the great importance of imbibed water as a controlling factor 



m protoplasmic phenomena. — Burton E. Livingston. 



Cultures of plant kusis, made by Freeman ^ during the three months 

 from March to June of the present year, are reported in the Annals of 

 Botany for September, The work was done under the direction of Pro- 

 fessor Marshall Ward at Cambridge University, and is in line with investiga- 

 tions instituted by Professor Ward, and in part already reported. Only 

 uredospores of Piiccinia dispersa E. and H. were used, obtained from but 

 two hosts, Bromus mollis and B,stenlis, representing two of the five sections 

 of the genus. These were sown upon forty species and varieties of Bromus, 

 of which twenty-two showed no infection. Of the remaining kinds five were 

 infected by spores from both sources, eleven were only infected by spores 

 taken from B, mollis, while B. sterilis was the only kind out of the forty that 

 could be infected with spores from B. sterilis alone. To secure these results 

 about fifteen hundred cultures were made. It is such thorough and accurate 

 work as this that will eventually give us a clear notion of the relationships of 

 our common cereal and meadow rusts.— J. C. Arthur. 



^ Dixon, H. FI., On the germination of seeds after exposure to high tempera- 

 tures. Notes from Bot. School Trinity Coll. Dublin 5 : 176-186. 1902. 



7 Freeman, E. M., Experiments on the brown rust of hxom^h{Pucdnia dispersa). 

 Ann. Botany 16:487-494. 1902. 



