165 



greatest growth to take place in the topmost third, less growth 

 in the middle third, and very slight or no growth in the bottom 

 third. In some plants he divided his topmost interval into two 

 parts and found that in many cases the topmost half grew less than 

 the one beneath, although there were a great many variations 

 from this. 



In conclusion, the typical Panacohis retirngis, grown under 

 green-house conditions, requires from 4 to 5 days for the com- 

 plete development of the fruit body after appearing above the 

 ground. The stem grows slowly at first, then very rapidly for 

 from 40 to 56 hours, then for about twenty-four hours slowly 

 again until it ceases. 



The pileus grows slowly but steadily at first and enters on its 

 most active period of growth just before this ceases in the stem. 

 The width remains slightly less than the length until this time. 

 It now broadens more rapidly and continues increasing at this 

 rate while the length increases only slowly. The pileus in many 

 cases continues its expansion after the stem growth has been 

 completed. 



Growth is no more rapid by night than by day. The growth 

 region of the stem lies near the top, the greatest growth taking 

 place a few mm. below the top of the stem. 



This work was undertaken at Cornell University, under the 

 direction of Professor G. F. Atkinson, to whom I am indebted 

 for many helpful suggestions and for the use of photographs of 

 the developing Panaeolus retirngis. 



Ithaca, New York, 

 July 7, 1906. 



BOSSEKIA OR RUBACER 



By p. a. Rydberg 



Dr. Greene ^' has replaced my generic name Rnbacer by Bos- 

 sekia Necker.f I wish to make a protest, not so much against the 

 replacement of the name as against the spirit and manner in which 



* Leaflets i : 210. Ap 1906. 

 f Elem. Bot. 2 : 9I. 1790. 



