220 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



new section is added to the apical portion during the seasonal activ- 

 ity, and the oldest portion is abandoned and cutoff from the surviving 



region, examples being furnished 

 by Arisaema (pp. 48, 50), Trillium 

 (pp. 181, 182), Arodes{^. 86), A^n- 

 orpkop/ialli{s{^. ^o),J^ilix(jp. 106), 

 Menispcrvitnn (p. 125), Onoclea 

 (p. 129), Osmunda (p. 132), Pel- 

 tandra (p. 144), Podophyllum (p. 

 150), Polystichum (p. 147), Ptcris 

 (p. 157), Viola (p. 186) and Wood- 

 wardia (p. 188). Plants of this 

 type seemed to be admirably adapt- 

 ed for several seasons activity in 

 uninterrupted darkness. The ac- 

 tion of the apical bud generally re- 

 sulted in the formation of a terminal 

 reunion of smaller diameter than 

 the normal, and as the rhizomes 

 or corms were cut away in the older 

 portions the underground mem- 

 ber left at the end of the season 

 of growth in darkness would be 

 smaller than the normal average. 

 The aerial organs sent up for such diminished underground mem- 

 bers were also smaller than the normal, and showed a tendency 

 to appear in lessened number. The most striking example of this 

 nutritive type is that of Arisaema (pp. 48, 50), the corms of which 

 were capable of four seasons of activity in the darkness under con- 

 ditions of fairly constant temperature as described in an earlier sec- 

 tion of this memoir. So far as the single set of analyses are to be 

 considered as representative, the proportion of water increases in the 

 aerial organs with successive etiolations, and decreases in the corms. 

 The repeated development of the plant in the dark room without 

 any accession of new material from the chlorophyl-apparatus 

 seems to lead to the conclusion that the stored material contains 

 the necessary constituents for cell construction, and the endurance 

 of any species of the conditions under which no new food may be 

 formed is primarily a matter of food supply. The capacity for such 



A B 



Fig. 161. Arisaema frt'p/iyllnm. A, 

 seedling after first growth in darkness. 

 B, seedling after second etiolation. C, 

 seedling after third etiolation. 



