The Scottish Naturalist. 151 



Gardiner, Dundee, Alex. Croall, Montrose, and Professer Dickie, 

 Aberdeen. The publication of Hassall's Fresh Water Algce in 1845, 

 marks an epoch in the study of these obscure organisms, so far as 

 English readers are concerned. This was followed, in 1848, by 

 Kiitzing's Species Algarum; which was succeeded and illustrated by his 

 nineteen volumes of plates. In his Species Algarvgi, he mentions a 

 plant, Hydrurus foetidus, as Scottish; but without citing authority or 

 indicating locality. I have searched through all the books I can 

 think of for information on this point. The plant is not uncommon 

 in other countries, but I wanted the information in regard to our own. 

 Strangely enough, two years ago Dr. Nordstedt, of the University 

 of Lund, and I found it in a locality which is visited every year by 

 numerous botanists, viz., the River Clunie, in the middle of the 

 village of Braemar. Still, of cpurse, that does not solve the difficulty 

 as to Kiitzing's information. Since the publication of these works 

 not a year has passed without additions of more or less importance 

 being made to our stock of knowledge. 



I shall now confine myself to Fresh Water Algae, particularly to 

 a few groups. I shall first make a remark or two on the Frotococcoids, 

 which embrace a number of so-called species. They are extremely 

 simple in form, which is more or less spherical. Each plant consists 

 of a single cell either floating freely by itself, or aggregated with 

 others into a more or less mucous mass. And their life history 

 appears to be equally simple with their form. They increase by cell- 

 division ; that is, the protoplasm in the cell separates into two 

 divisions ; the two halves are pushed apart, and each assumes the 

 spherical form, and floats off free. This operation is repeated 

 again and again. Now the question may be asked, and has been 

 asked : Is this the whole life history of these minute objects, (only 

 a few ten-thousands of an inch in diameter), or is this merely a 

 stage in the history of some higher plant ? On this subject Dr. 

 Schaarschmidt, Lecturer in the Royal Hungarian University at 

 Kolosvar, in a recent paper says : " What some years before many 

 conjectured as possible, is by recent observers asserted as true not 

 only for the Cyanophyceous but for the Chlorophyllopliyceous Algae, 

 viz., that many, if not all, the unicellular species, and some of the 

 composite species of the Cyanophyceous Algae, and, perhaps, of the 

 Chlorophyllophyceous, are merely stages in the life history of higher 

 plants. These states being fixed, the different forms have been 

 defined and distinguished as different species. It will, probably, be 

 finally found that some of the so-called species of Gloeocapsa, 

 Ckroococcus, <fec, as also of Cylindrocystis, Protococcus, &c, have their 



