MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 3 1 



tests. The general subject was treated more fully in an extended 

 paper in the same year in which the following additional points are 

 made : Etiolated plants have the outer walls of the epidermis with- 

 out the papillose convexities characteristic of other individuals of the 

 same species grown in light. Intercellular spaces are lacking in 

 mesophyl of etiolated leaves, and is composed of isodiametric cells. 

 The palisade cells show some differentiation. Stomata were ob- 

 served by Teodoresco to be more numerous in a given area than in 

 normal specimens, and also to be smaller. The notable lack of 

 differentiation of tissues in etiolated plants was observed and atten- 

 tion was called to the lack of formation of the generative layers, and 

 of secondary tissues. Similar lack of development of xylem and of 

 bast fibers was noticed. 



The multiplication of observations upon fungi in which light is 

 found to exert no influence is a notable feature of the most recent 

 investigations. Klebs ^^^ joined in such results and found that growth 

 of the vegetative organs as well as the reproduction of many forms 

 was utterly uninfluenced by the radiations. Furthermore the growth 

 of sporophores in many species occurred absolutely indifferently in 

 light and darkness. The single instance of retardation of growth of 

 the sporophore of Phycomyces and Mucor by Vines and Stameroff 

 does not have the concurrence of Bullot,"" who affirms that these 

 organs grow more rapidly in continuous light than in darkness. 

 Light has been found necessary for spore formation except in the sin- 

 gle example cited by Klein. In such observations the critical points 

 are well defined and the intensity of illumination may be increased 

 to a point where an unfavorable action is exerted, and the photo- 

 tropic behavior reversed. Klebs has pointed out the necessity for the 

 strictest control of experimental tests of fungi in light since the separ- 

 ate results of altered transpiration and nutrition may mask or alter 

 the effects of the illumination. These results are confirmed in the 

 main by Ternetz,"^ and other investigators quoted by Klebs and 

 Ternetz. 



109 Klebs, G. Zur Physiologic der Fortpflanzung einiger Pilze. Jahrb. f . Wiss. Bot. 

 35 : 140. 1900. 



""Bullot, E. Sur la croissance et les courbes du Phycomyces. Ann. d. 1. Soc. 

 Microscopique d. Beige, 21 : 84. 1S97. 



"'Ternetz, C. Protoplasmabewegungung Fruchtkorperbildung bei Ascophanes 

 carneus'Pers. Jahrb. f. Wiss. Bot. 35= 273. 1900. 



