excellent friend Mr. Thwaites. It grows, as that gentleman in- 
forms us, in watery places, such as produce the Ceratopteris tha- 
lictroides, Brong., and we shall find it probably as difficult to 
cultivate, for a series of years, as we do the Ophioglossum, Botry- 
chium, etc., which, it is possible, judging from the fleshiness of 
their roots, may be all in some sense parasitic. 
It must be a great love of species-making that induced the late 
Dr. Presl to describe the three specimens distributed in the col- 
lections of Mr. Cuming from Luzon, as three distinct species ! 
One of these he afterwards acknowledged to be the same as his 
Botryopsis Mexicana of ‘ Reliquie Henkeane ;’ and on finding 
that it was not really a Mexican plant, and not distinct as a 
genus from Helminthostachys, he had called it H. crenata. 
T 
Prats 28. Fertile plant of Helminthostachys Zeylanica, Kaulf.,—natural size. 
Fig. 1. Portion of a frond, to show the venation. 2. Portion of a spike, with 
clusters of capsules. 3. Single cluster of do.,—all magnified. 
