Notes and News 
PROTHALLIA OF CAMPTOSORUS 
Readers of the JourNau have not found much in its 
pages about the prothallial stage of any sort of fern. 
A reference to a paper on this stage of fern life may there- 
fore be of interest, especially as it deals with the pro- 
thallia of one of our most interesting and less common 
species, the walking fern. 
Under the title ‘‘ Resistance of the prothallia of Camp- 
tosorus rhizophyllus to dessication,’? F. L. Pickett dis- 
cusses a series of experiments carried on with the pro- 
thallia of this fern which go a long way toward explaining 
the ability of the walking fern to grow and thrive in 
situations frequently subject to extreme drouth. These 
experiments are also suggestive as regards the mainten- 
ance of other ferns which frequent dry situations like 
Pellaea atropurpurea, which seems often to like best 
the most exposed cliffs. 
Briefly the experiments were as follows: Prothallia 
of this species were grown from spores and then were 
subjected to periods of artificial drying, varying from a 
few days up to two months. It was found that vigorous 
prothallia could stand continous drying of more than 
two months and still be able to resume growth and to 
produce the sporophyte stage when moisture was again 
applied. A difference was noted however, as regards 
the behavior of the prothallia in direct sunlight and in 
diffused light, the latter being much more favorable. 
Some of the details noted incidentally are also of in- 
terest. For example, spores taken from leaves collected 
October 26th, and sown November 22nd, germinated 
by December 17th. Under normal moist conditions 
those in direct sunlight showed more rapid growth at 
1Bull Torrey Club 40: 641-645. 15 Nov. 1913. 
11 
