July 7, 1905.] 



SCIENCE. 



15 



northern Pacific Ocean, or at least here was 

 where their greatest evolutionary progress 

 occurred. Sixty-four species occur here and 

 fifty-five are found nowhere else. All the 

 twenty-two genera occur in the northern 

 Pacific. In the southern hemisphere, where 

 the temperature conditions are favorable to 

 the growth of these algse, as is shown by the 

 prodigious size attained there by Macrocystis, 

 and by its extreme abundance, only three 

 genera occur containing but fourteen species, 

 all but two restricted to the southern hemi- 

 sphere. These species are probably descend- 

 ants of forms that crossed the equator during 

 the glacial period when the ocean had a much 

 lower temperature in the tropical zone. That 

 period has occurred in the southern hemi- 

 sphere; at least it is shown by the failure of 

 Macrocystis to cross into the northern Atlan- 

 tic Ocean, where it would find a larger region 

 admirably adapted for its growth. 



These alg^ attain the greatest length of any 

 plant, Macrocystis reaching a length of 400 

 to 700 feet or over. Some of the forms, such 

 as Palagophycus and Nereocystis, are annuals 

 and must grow much faster than any other 

 organisms in order to attain in the course of 

 a few months their enormous length (100 to 

 200 feet or over). 



The large size and high differentiation of 

 tissues attained in this group, and especially 

 the occurrence of well-marked species and 

 very distinct genera, render it highly probable 

 that sexuality occurs in spite of the prevailing 

 opinion of algologists to the contrary. 



racenia purpurea, Drosera rotundifolia, D. 

 intermedia, Eriocaulon decangulare, Utricu- 

 laria sp., Castalia odorata (in three or four 

 inches of water), Lycopodium adpi-essum and 

 Blephariglottis cristata have been found. Just 

 below the bog is a shallow pond in which 

 occur Brasenia peltata, Potamogeton sp., 

 Nymphoea advena, Castalia odorata, and a 

 rapidly increasing colony of Marsilea quadri- 

 folia introduced six or eight years ago. 

 Around its margin Blethia and several heaths 

 are found. No Isoetes has ever been discov- 

 ered, in spite of apparently ideal conditions. 

 In the wet woods are very large colonies of 

 Woodwardia areolata, Nephrodium simulatum 

 and Osmunda cinnamonea, together with the 

 form glandulosa, for which this is the type 

 locality. N. cristatum, N. hoothi and N. 

 spinulosum, Woodwardia virginica, Smilax 

 walteri. Magnolia virginiana, Blephariglottis 

 blephariglottis, Perularia flava, and many 

 other plants are found. In the rather swift 

 stream with gravelly bottom Vallisneria spi- 

 ralis is plentiful. Practically none of the 

 common spring flowers usually found in low 

 rich woods are known to occur there. Many 

 other common plants are also missing, one of 

 the most notable being Equisetum arvense, 

 which is abundant along railroads, etc., in 

 Baltimore County, but has not been seen in 

 the region under discussion. The absence of 

 Typha in the bog was especially noted, and 

 in the discussion which followed the paper the 

 fact was brought out that it is rarely if ever 

 foimd growing with Sphagnum. 



The Flora of a Sphagnum Bog : C. E. Waters. 

 An account was given of a sphagnum bog 

 in Ann Arundel County, Maryland. The 

 characteristic plants of the bog proper, of the 

 low wet woods along the stream flowing 

 thrpugh it, and of the surrounding dry woods, 

 were shown to be of unusual botanical in- 

 terest. In the dry woods Quercus prinoides, 

 Q. nana and Castanea pumila, together with 

 Kalmia angustifolia. Vaccinia and other 

 heaths, are abundant. Iris verna, Chrosperma 

 mu^ccetoxicum, Gaultheria, Rhus toxicoden- 

 dron and R. radicans, etc., are common. In 

 the more open parts of the bog are found Sar- 



The twenty-eighth regular meeting of the 

 Botanical Society of Washington was held at 

 the Portner Hotel, April 29, 1905. The fol- 

 lowing papers were presented: 

 Recent Results with the Use of Copper in City 



Water Supplies: Karl S. Kellerman. 



The use of copper for eradicating algal pol- 

 lution is now generally recognized as the most 

 practical successful method of dealing with 

 this troublesome phase of water engineering. 



Copper has been proposed, also, as an agent 

 for disinfecting water supplies contaminated 

 with pathogenic bacteria, and considerable dis- 

 cussion has been aroused as to the advisability 



