1895. ] Section G, A. A. ALS. 411 
isms possessing (in their vegetative state) a cellulose invest- 
ment; animals are organisms possessing (in their vegetative 
state) a proteid investment, either actual or potential. 
MINOT, CHARLESS.: Rejuvenation and heredity.—The paper 
traced the réle of the embryonic type of cells in plants and 
animals as a necessary predisposition of structure for the ac- 
tion of heredity. -The réle of these cells in animals and 
plants in reproduction and regeneration was discussed, espe- 
cially to show that their functions render it impossible to ac- 
cept Weismann’s theory of heredity. It was pointed out that 
the theory in all essential particulars is Nussbaum’s and not 
Weismann’s, whose attitude towards his critics was incisively 
criticized. 
SWINGLE, WALTER T.: Fungus gardens in the nests of an 
ant near Washington, D. C.—The nests of Atta tardigrada 
Buckl. near Washington are small subterranean cavities 
6-10™ in diameter, situated from 2 to 15 or 20™ below the 
surface. Almost the whole cavity is filled with a grayish ma- 
terial loosely and irregularly cemented together. A large 
part of this substance consists of the excrements of a leaf- 
eating larva which the ants carry in. On these pellets the 
ants cultivate a fungus whose free hyphe end in glistening 
spherical knobs similar to those described by Moller from the 
ant gardens of southern Brazil and designated by him ‘‘kohl- 
rabi.” They are 22-524 wide and 30-56u long, while the 
supporting hyphe are only 4-8 in diameter. No septum 
divides the kohl-rabi from the stalk. The whole appearance 
of the fungus is strikingly similar to that described by Moller 
(except in being nearly twice as large) and it is not impossi- 
ble that it will prove to be the same species. 
BAILEY, L. H.: Variation after birth.—Read by title. 
COVILLE, FREDERICK W.: Potsoning by broad-leaved laurel, 
Kalmia latifolia.—Read by title. 
MONDAY AFTERNOON, SEPTEMBER 2D. 
MacDoucaL, D. T.: The transmission of stimult-effects 
tn Mimosa pudica.—The author showed that Haberlandt’s ex- 
planation of transmission of stimuli by the ‘‘Schlauchzelle” 
was not tenable. Stems or petioles killed by a steam jacket 
for 5-10™, and those from which the phloem region (includ- 
ing the ‘‘Schlauchzelle”) had been removed, were still able to 
transmit the stimulus-effect. Sudden application of a hydro- 
static pressure of five to twenty atmospheres and sudden di- 
