PROTHALLIA OF LYCOPODIUM IN AMERICA 
II. L. LUCIDULUM AND L. OBSCURUM 
VAR. DENDROIDEUM 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY 300 
EARLE AUGUSTUS SPESSARD 
(WITH PLATES XVI-XVIII) 
In the first paper (4) there was included a short description 
of a single prothallium of L. lucidulum; also reference to what was 
thought at that time to be the prothallium of L. obscurum vat. 
dendroideum. ‘The question raised then was later settled in a 
short announcement published about a year later (5). It is the 
purpose of the present paper to describe fully the hitherto unde- 
scribed prothallia of these two species of Lycopodium, and to draw 
such comparisons as may seem justifiable. 
Material and methods 
The method of collecting described in the first paper has been 
followed almost entirely. It was found neither desirable nor 
practicable to sift or to wash the soil. The smallest desirable 
prothallia may be secured by the simple means of picking with 
curved forceps. A patch of soil in the form of a square or rec- 
tangle was removed to a depth of 4 or 5 cm., placed in a basket, 
and carried to the laboratory, where the prothallia were picked out. 
At frequent intervals small portions were placed under a dissecting 
microscope for the detection of the very youngest stages. Lying 
prone upon the ground is quite as good a method, save for the 
fact that one gets extremely tired after four or five hours of painstak- 
ing search. 
For fixing, various mixtures of chromic-acetic-osmic acids were 
used, as well as formalin-alcohol. While the former proved to be 
somewhat better than the latter, it was not determined what is 
the best mixture. 
Botanical Gazette, vol. 74] [392 
