50 MEMOIRS OF THE NEAV" YORK BOTANICAL GARDEN. 



etiolated ii. Stomata of normal scapes measured lo by 12 in one 

 series and 10 by 11 in another. Stomata of etiolated scapes meas- 

 ured 8 by 10 and 8 by 11. The stomata were slightly open when 

 examined in water. 



Corms surviving the first etiolation were given a period of rest, 

 when they were again set in action, and produced buds of not more 

 than half the length of the first etiolated growth. No flowers were 

 formed in this second etiolation, however. Many of the corms were 

 sound and alive after the second etiolation, and remained quiescent 

 two years and are still dormant at the date of preparation of this 

 memoir (June, 1902). 



Attention has been called to the saprophytic etiolated growth of 

 the seedlings oiAj-isacma Dj'acontiiun in a previous paper. The ger- 

 mination of the seed results in the formation of a hypocotyledonary 

 stalk which is pushed down into the soil carrying with it the plumule 

 which remains in an undeveloped condition. The base of the hypo- 

 cotyl soon begins to swell and the surplus food in the seed is with- 

 drawn into the tuber thus formed, which bears the quiescent plumular 

 bud at its apex. The entire season is thus spent underground, and 

 the saprophytic existence of the seedling is much prolonged. ^^"^ 



Arisaema triphyllum (L.) Torr. 



Arisaema irifhyUiim lent itself most readily to etiolation experi- 

 ments and it was used in obtaining data on several general questions 

 in the investigations. Several hundred cultures have been made in 

 the dark chamber, and this plant has been under continuous observa- 

 tion from 1895 to 1902. 



Corms placed in the dark chamber after a proper resting period 

 would soon begin to show indications of activity. Ordinarily the 

 terminal bud of the corm elongates to a length of 5 to 7 cm. and 

 then splits, allowing the leaves and flowers to escape. The sheath- 

 ing bases of the two leaves enclose the base of the scape to a dis- 

 tance of 4 to 8 cm. from the corm, and the petioles attain a length 

 of 15 to 75 cm., which is something longer than the scape. A second 

 scale sheathes the base of the bud and has a length of 2.5 cm. A 

 third basal scale rarely reaches a length of over a centimeter. 

 Marked departures from this procedure were shown by etiolated cul- 



'^"MacDougal. Seedlings of -i4r/5«e;«a. Torreya, i : 2. 1901. See also Rennert, 

 R. J. Seeds and Seedlings of Arisaema triphyllutn and Arisaema Dracontium. Bull. 

 Torrey Club, 29 : 37-54. 1902. 



