146 



SCIENCE. 



[N. S. Vol. XX. No. 500. 



diatom. It was suggested that part of this 

 action may be due as well to Crenothrix. 

 There is little of vegetable remains except at 

 the top of the bog. Sphagnum makes up a 

 comparatively small part of the peat bog 

 vegetation as seen in the localities mentioned, 

 and sphagnum peat is not so highly prized for 

 fuel. A small Oarex seemed to be the prin- 

 cipal peat forming plant. Two species of 

 Drosera grow in profusion and the heather 

 and ling thrive very well and contribute con- 

 siderably to the peat. Pteridium and several 

 small ferns are rather common. Sphagnum 

 and many fresh-water alg83 grow in the holes 

 and ditches, and from such places West has 

 made fine collections of algse, especially des- 

 mids. Peat bog soil has been found to be 

 very sterile and at least two years are required 

 to reclaim it, the method including throwing it 

 up and exposing it to the air, and the applica- 

 tion of fertilizers and lime. The cause of this 

 sterility is not clearly understood, and is, per- 

 haps, due to the lack of some of the necessary 

 mineral salts and to the fact that the nitro- 

 genous materials may not be in the best avail- 

 able form for plant nutrition. Some of the 

 reclaimed peat bogs are very fertile lands, but 

 if neglected they quickly run back to their 

 sterile condition. If cultivation ceases, the 

 Pteridium, heather and carices come back in 

 a few years. 



The second paper of the evening was by Dr. 

 Marshall A. Howe, under title of ' Eemarks 

 on some "West Indian Marine Alg».' The re- 

 marks were based chiefly upon specimens col- 

 lected by the speaker in March and April of 

 the present year on the Florida Keys and the 

 Bahama Islands, supplemented by specimens 

 from Bermuda and Porto Eico and also by 

 some obtained on a previous visit to Key West. 

 The discussion was confined to the families 

 Caulerpaeeas and Codiaceas, members of the 

 order Siphonales and class Chlorophyceje. 

 The family Caulerpacese, according to the 

 more recent writers, consists of the Single 

 genus Gaiilerpa, with probably sixty or more 

 well-defined species, including plants of a 

 great diversity of form and habit. Some of 

 the earlier phycologists, impressed by these 



evident difi'erences, suggested generic segrega- 

 tions, and it is probable that some of the pro- 

 posed genera are as well limited as are many 

 of the current genera among the Agaricacese. 

 There is, however, not such an unwieldy num- 

 ber pi species to afford an excuse for generic 

 splitting as is the case with the agarics, and 

 there is practically nothing but habit and ex- 

 ternal form to lay hold of in limiting species 

 and attempting generic segregations. Speci- 

 mens were shown illustrating the principal 

 sectional or subgeneric groups. 



The Codiacese were illustrated by specimens 

 of Codium, Avrainvillea, Penicillus, Bhipo- 

 cephalus, JJdotea and Halim,eda. The genera 

 Penicillus and Bhipocephalus are especially 

 well represented in the Bahama Islands. Four 

 species of Penicillus and two of Bhipocephalus 

 were shown, all of which were found growing 

 within a mile radius in Bemini Harbor, Ba- 

 hamas. One of these is supposed to be the 

 species described from the Bahamas by 

 Decaisne in 1842 as Penicillus oblongus and 

 apparently not met with in the meantime. 

 This species was transferred to the genus 

 Bhipocephalus by Kuetzing. In reality it 

 stands between the genera Penicillus and 

 Bhipocephalus and weakens the distinction 

 between them. It is easily a Bhipocephalus 

 when it is young, but as it gets older becomes 

 more like a Penicillus and might then be 

 casually passed by as a form of the common 

 Penicillus capitatus. The head, however, is 

 usually more oblong than in that species, the 

 branching of the threads of the brush is char- 

 acteristic and the arrangement of the threads 

 in the apical or younger part of the brush is 

 always distinctive. 



Among the species and forms of Ealimeda 

 exhibited was one from the Plorida Keys 

 which is soon to be described as a new species. 

 This has been confused with Halimeda Tuna 

 by both American and foreign students of the 

 genus, but is readily distinguished from that 

 and other described species by the fact that 

 the surface of each cortical tube or ' cell ' is 

 drawn out into a strong spine. 



William T. Horne, 

 Secretary pro tern. 



