153 



chlorophyll in 0. vulgatum when the prothallia were exposed 

 to the light, but did not observe any flattening of the apex. 

 Owing to the very small number of active prothallia found by 

 the writer, he was nuable to test the power of developing 

 chlorophyll in (). nioluccanum. In one case a prothallium was 

 found in the garden at Buitenzorg growing almost at the 

 surface of the ground. There appeared to be a very small 

 amount of chlorophyll in this, but it was not certain that 

 such was really the case. The occasional appearance of chro- 

 matophores in the germinating spores harmonizes with the 

 capacity of the older prothallia to develop chlorophyll under 

 the stimulation of light. 



The small size of the prothallia and the cessation of growth 

 after the sporophyte is formed indicates that the gametophyte 

 lives only for one season, which is proba])ly the case also in 

 Helminthostachjs. In this respect 0. inoluccanum and its allies 

 differ markedly from 0. pendulum and 0. vulgatum^ where the 

 gametophyte may live for many years. 



At Hakgala, in Ceylon, an undetermined species of Opli^^o- 

 glossum of the type of 0. reticulaiUm was common. A careful 

 search finally brought to light a small number of prothallia 

 (Figs. 30 — 31) which resembled closely those of 0. moluccanum, 

 and the young sporophyte is also of the same type. The 

 material was too scanty to make a further study possible, but 

 from the external appearance it is likely that its structural 

 details would closely resemble those of 0. mohiccanum. 



Lang (loc. cit.) discovered the prothallia of O. pendulum in 

 the Barawa Forest reserve in Cevlon, and the waiter visited 

 the same locality. Although large masses of the older sporophyte 

 were found, they grew high up on the branches of trees and 

 it was difficult to remove the mass of humus in which they 

 were growing, as it was excessively dry and fell to pieces. If 

 any prothallia were present they must have been completely 

 dried up. At any rate, careful search through such of the 

 humus as could be secured yielded no results. In the botanical 

 gai'den at Singapore a fine growth of the plant was found 



Ann. Jaid. bot. Buitenz. 2e Se'r. Vol. VI, 11 



