426 BOTANICAL GAZETTE. 
cloths put in, the glass cover adjusted and the whole boiled over a lamp for a 
short time. This is necessary in order both to thoroughly wet the cloth and to 
kill any mold or other germs. When again cool, adjust the cloths on the brass 
rods, and put in the seeds. Each fold will hold twenty-five large seeds, like 
beans, and a hundred or more small seeds. Water is placed in the pan, but not 
enough to touch the folds of cloth; the four flaps drop down into it, however, 
and keep the cloths sufficiently wet by capillarity, which is increased by the 
long nap on the under surface of the cloth. The folds are numbered consecu- 
tively and the record kept by the numbers. 
The advantages in a pan of this kind are the facility with which the seeds 
may be examined and counted, the thorough and uniform moisture of the 
seeds throughout the longest trials, its lightness and cleanliness. It is neces- 
sary to renew the cloths from time to time, as they will slowly rot out, even 
with the best of care. 
This has been recently introduced, I am told, at the U.S. Department of 
Agriculture, and at one or two other places, under the name of the Geneva 
germinator.—J. C. A. 
A Convenient Laboratory Plant.—One of the plants that has proved 
most instructive in our laboratory is a Mucor%*of the Rhizopus section, which 
springs up spontaneously and can be left growing almost indefinitely on bread. 
reshly cut wheat bread it makes a prompt and rank growth when 
covered by a tumbler, and illustrates heliotropism very strikingly if grown so 
as to be strongly shaded on one side and well lighted on the other. 
The best cultures for study are usually obtained by inverting tumblers over 
pieces of rather stale bread, which often fails to show the mold for a number of 
days (sometimes a week or more). When this appears it usually grows slowly, 
so that the plants are not 
a 
onto the glass, usually reach- 
ing a length of a half inch 
or less, but occasionally be- 
th 
touch the glass, they attach 
themselves by short rhizoids 
and send up tufts of ( usually) 
2 to 5 pale-brown fruiting 
Culture of a Mucor under a tumbler. 
the piece of bread is small, they are scattered over the glass so as to be acces 
sible for observation, without disturbance, several weeks, and at first manifest 
a slightly developed negative geotropism, 
though the bread appears quite dry, it really contains a considerable 
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