AdKK TI.TritAI. l',<tTA\V. 7.'^.'^ 



Specialization and the origin of alternation of host plants in the Uredinese, 

 W. Krikc; {S'dttinr. Wi'linschr.. i.i [I'J'is). Vo. .Ul, />/>. '>C>t-')l.i, /ii/x. •>). — A re- 

 view is yiven of reeent iiul)!l<-;itioiis relatiuii to si)ecializatioii among Oei'tain 

 species of rusts. 



The present status of agricultural plant breeding, C. Fruwirtii {Med. 

 Klinik, // (HKhS), A'o.s. /.J. /)/*. r,(>l-.',().i; /J. /<//. .7'// -.7'/J; /(/, /</>. ')S<.)-:)91).—The 

 history of i)lant l)retHliiij? is lirieHy reviewed and the different methods of plant 

 improvement hy means of selection and hybridization are described. Mendel's 

 law is considereil in this connection and the use made of grafting is also noted. 



Notes on bud mutations of Solanum maglia, E. IIeckkl (Compt. Rend. 

 Acad. Sci. [/'«mi, 1.',7 (tHOS), No. l.'>, pp. Ulo-dll). — For several years the 

 author has been carrying on exjieriments with a number of species of Solanum 

 to determine if i)ossii»le the origin of the cultivated potato, and in the present 

 jiaiier he gives an account of the third generation of a bud sport of >s'. ni<i(/lin 

 that appears to have become fairly constant. 



The author found that by growing (his species in soils that were highly fer- 

 tilized with chemical fertilizers and hen manure the plant was caused to mutate, 

 producing tubers of various forms and colors. Where grown under other con- 

 <litions, the plant showed no variation from the wild type. The third genera- 

 tion nuitants grown alc^ngside of ordinary potatoes showed very marked resist- 

 ance to the Phytoi)htbora disease, and the author believes that be has secured 

 material not only of biological interest but also of i)ractical value, since the new 

 I'orm appears to be adapted to wide variation in cultural conditions and is 

 resistant to disease. 



On the influence of wound stimuli on the formation of adventitious buds 

 in the leaves of Gnetum gnemon, .J. van Beuskkom (A'. Akdil. Wctcnsch. 

 Amstrnlaiiu Proc. Scet. Sri.. 10 (1907), pt. 1, pp. 168-181).— The occurrence 

 of adventitious buds on the leaves of a specimen of Gnetum has been under 

 observation for .S((me time at T'trecht, and the author has undertaken to ascer- 

 tain the cause of their abnormal development. 



The formation of tlu'se l)uds was traced to punctures of a si)ecies of 

 As]»idiotus. In their early aspect the ahnormal tissues are yellowish, resem- 

 liling in some degree the stigmonose of carnations, which has been shown by 

 Woods to l»e due to aphid punctures (E. S. R., 12, p. 4(»()). T'nlike the carnation 

 disease, there does not appear to be any irritating excretion on the part of the 

 insec-t, and it is concluded that the leaf of G. gnemnn may be stinndated to the 

 formation of iiitinnescences and hence adventitious buds by wounding, providing 

 tills is very slight, and that consequently the process is to be regarded as a 

 reaction on the wound stinnibis. 



Some notes on grafting varieties of beans, L. Danirl {('(unpl. h'nul. Acad. 

 Kci. f/'on.y|, /.'/? ( HWS), \o. 2, pp. / '/J-/f'/).— The author f<.und in experiments 

 with 2 rac«'s of beans grown in Knop's solution that one was very subjin-t to 

 chlorosis, the leaves fell early, and llowering was retarded, while the ntliei- 

 developed normally. He then made reciprocal grafts and found that tlu> char 

 acferistics of the stock were transmitted in considerable degree to the gnift. 

 The chlorotic foi-m when grafted upon the other developed normally and 

 llowered early and aliuMdant ly. Tlie form that was green and in every way 

 normal when grown upon its own roots when grafted \i|ion the chlorotic stock 

 was alTn-led with chlorosis, the leaves were poorly developed, and llowering was 

 retardiMl. In addition (o these gross dilTerences, niicroscopic tr;instormations 

 w«'re also noted. 



A method for the quantitative determination of transpiration in plants, 

 <^ F. Fri-.iman {lUit. da:.. ',i; (lUns). \i,. ,». pp. //X- /?.'». //>/. /».— A form of 

 transpiratinii apparatus is deserihed wliieli is a niodilicalidu .MMd adai't:il ion of 



