84 BOTANICAL GAZETTE [jaxxjarv 



chromogens in 67. Their existence in three of the other four species can be demon 

 strated by other methods. He mentions various fungi that other investigators 

 have shown to contain chromogens, as well as various other higher forms. The 

 points in the literature of this very important subject are briefly and clearly stated. 

 The same investigator finds 1 * that portions of leaves in a 20 to 25 per cent 

 saccharose solution for seven days show a great increase in respiratory chromogens, 

 over checks immediately taken from the plant, or those kept in distilled water for 

 the same length of time. Illumination during the treatment increases somewhat 

 the chromogen production. If this treatment is continued for 17 days in light, 



" ms of leaves take on a bright-red color. The color he believes originates 

 from the oxidation of respiratory chromogens. He holds that the sugar greatly 

 increases the respiration and therefore the respiratory chromogens. Whether 

 the chromogen shall become chromatic depends upon whether the oxidases 

 exceed the reductases in activity. In long-continued exposures this seems to 

 occur, hence the red color. He believes that Overton's explanation of spring and 

 autumn coloration of leaves is not complete with the consideration of low tempera- 

 ture (as lowering respiration) and abundant supply of sugar as the factors, and 

 considers the relative activity of oxidases and reductases on the chromogen prod- 

 ucts of respiration as very important.— William Crocker. 



porti 



Graft hybrids.— Winkler 



known 



uses 



The method is to graft one species on another in the ordinary manner, and after 

 the scion has "taken," to sever the stem at a point where the tissues of both 



species will hp mr A<4t»> n +:.„i „i ^. ^i . ,. . «t.i...„* 



species 

 will 



Adventive shoots then grow out from this cut surface. These 

 :ters of either species according to the point they grow from, 

 bhoots arising from the point of contact of the two species gave a peculiar result, 

 which may be described. A scion of Solatium nigrum was grafted in this way on a 

 seedling of S. lycopersicum, and the shoot in question, originating from the point 

 oi contact of the parental tissues, bore leaves having on one side of the stem the 

 characters of S. nigrum, and on the other side those of S. lycopersicum. In cer- 

 tain cases where leaves were situated on the meeting-line of two kinds of cells, 

 one-naif of a leaf showed the characters of either parent. Winkler proposes to 



organisms 



and for this plant proposes the name Chimera Solanum nigrolycoperskm- 

 tie concludes that the cells of two different species may come together in other 

 man a sexual way, and thus serve as the starting-point for an organism which 

 shows simultaneously the characters of both parent species.-R. R. Gates. 



Rer ^^u T' W ,V ^^ diC Bildung der Atmungschromogene in den Pflanzen- 

 Ber. Deutsch. Bot. Gesells. 26a : 389-394. I9o8 . g 



ZhTt' E c n ANS ' ^^ ^"Pfl'Mtarde und pflanzliche Chimaren. Ber. 



Deutsch 



