252 BOTANICAL GAZETTE [march 



include (1) crossing under controlled conditions, (2) selection of fluctuations, and 

 (3) selection of wider variations and a study of ways of causing them, graft hybrids 

 being a possible method. — R. R. Gates. 



illuminated. 



aluminum. — Fluri 

 :h from Spirogyra 



permeable 



tic agents. The disappearance of the starch is probably due to the joint action 

 of three effects of these salts: loss of sugar through the permeable protoplasm, 

 the increased diastatic action, and the slower photosynthetic activity. If glucose, 

 glycerin, or isodulcitol is mixed with the aluminum salt, the salt does not then 

 render the protoplasm permeable. — Wm. Crocker. 



Transpiration and water storage. — Shreve 21 finds 



j 



mid 



phyte which does not store water, but grows at the top of the rainy forest. Stelis 

 reduces its transpiration almost to nothing when forced to draw upon the stored 



With 



sgular transpiration. — William 



Branch cankers of Rhododendron.— Von Schrenk 22 describes some interest- 

 ing swellings of the branches of Rhododendron maximum that are produced where 

 dead twigs have fallen. The healing layer starts to develop at a distance from the 

 base of the fallen twig, and in a few years a large swelling results. The chief 

 interest in the phenomenon arises from the fact that a gall-like structure is pro- 

 duced without the intervention of a parasite.— H. C. Cowles. 



Virescence in Oxalis.— Hus'3 has been studying plants of Oxalis stricta with 

 K^,-,k + ,,.... . J or . , .1 ,\>c While 



the green petals approach sepals in 



erw 



While 



other 



amed 



characteristics of the ordinary petals. The new form, which has been named 

 Oxalis stricta viridiflora, is constant from seed, and is to be made the object o 



careful study.— H. C. Cowles 



20 Fluri, Ma 

 99:81-126. 1908. 



21 Shreve, Forrest 



s von Aluminiumsalzen auf das Protoplasma. 

 ;piration and water storage in Stelis ophiogt"*** 



22 Schrenk, H. von, Branch cankers of Rhododendron. Mo. Bot. Gard. 

 18:77-80. 1907. 



2 3 Hus, H, Virescence of Oxalis stricta. Mo. Bot. Gard. Rep. iS:9r lc& ' I9 ° 7 ' 



Plant World 11:165-172. I9o8 . 



