THE GAMETOPHYTE 



contents appear opaque and obscures more or less the centrally placed nucleus. 

 A marked exception to the ordinary type of spore was that found in an undetermined 

 species of Ophioglossum collected at Buitenzorg in Java. This was supposed to be 

 O. moluccanum, with which it was growing, but a comparison with typical specimens 

 of the latter species showed marked differences, the most striking being the spores, 

 which were larger than in the type, had much less dense contents, and were espe- 

 cially notable in that they had regularly two nuclei, a condition unique, so far as I 

 know, among the ferns. (See Campbell 8, fig. 157.) The granular contents of the 

 spores include numerous albuminous granules, together with more or less starch 



and oil. 



GERMINATION IN OPHIOGLOSSUM. 



The first successful attempts to germinate the spores of Ophioglossum were 

 made by me in 1892, when ripe spores of the epiphytic 0. pendulum were collected 

 in Hawaii and brought to California. This species was found in Hawaii, growing 

 usually upon the trunks of tree ferns, and the spores were sown upon bits of the 

 bark-like masses of roots, which in the commoner tree ferns of Hawaii (species of 

 Cibotium) cover the trunk with a thick, felted mass. These masses of roots were 

 kept in jars, and the spores were sown upon them, a good many of them germinating 

 in course of time. The germination was very slow, the spores often remaining 

 unchanged for months, and none of these young prothallia developed beyond the 

 stage with three cells. This failure to develop further was undoubtedly due to the 

 fact that they did not become infected with the mycorrhiza, which is essential to the 

 full development of the prothallium. 



In 1906 ripe spores of the same species were collected in Ceylon and Java. 

 In Ceylon spores were secured at the botanical garden in Peradeniya and in the 

 Barrawa Reserve Forest near Hanwella, where Lang obtained his material. In Java 

 the spores were mostly collected at Tjibodas. In all of these later experiments the 

 spores were sown in humus collected from about the base of the spore-bearing 

 plants. These masses of wet humus were kept in stoppered bottles. 



As in the earlier experiments, 

 the germination was slow, the first 

 germinating stages being found only 

 after a month or more, and in some 

 cases the spores remained un- 

 changed for a very long period. The 

 bottles containing the spores sown 

 upon the humus were brought back 

 to California, and a recent exami- 

 nation (September 1909) showed a 

 considerable number of apparently 

 normal spores, as well as living 

 three-celled prothallia, presumably 

 the result of comparatively recent 

 germination. 



Spores sown in Tjibodas on 

 April 18, 1906, were first found 

 germinating at Buitenzorg on May 

 24, germination at this time being pretty well advanced. On June 3 a number of 

 these had three cells. The germination (fig. i) in all cases corresponded closely with 

 the writer's former observations and closely resembles that which we shall see pres- 

 ently in Ophioglossum moluccanum. In no case could any chlorophyll be detected, 



A. Germinating spore of Ophioglossum pendulum. X360. 



B. Optical section of A. 



C. Three views of a very young gametophyte of 0. pendulum, showing 



infection by mycorrhizal fungus. X360. 



