274 NOTES AND MEMORANDA. 



its formation of a separate section for microscopy, and wo have no 

 donbt tliat the results will even excel those whicli we have long since 

 reported from the last session. The • American Naturalist ' suggests 

 to the local committee the propriety of supplying a room with proper 

 light and substantial tables for the occasion. We hope this recommen- 

 dation will be attended to. 



Colossal Fossil Sea-weed. — From the microscopic examination of 

 the structure of specimens of the fossil trunks described under the 

 name of Proiotaxifes Logani, and which Principal Dawson affirmed, in 

 his Bakerian lecture before the Eoyal Society, to be the oldest known 

 instance of coniferous wood, Mr. Carruthers has (says ' The Academy ') 

 discovered that they are really the stems of huge Algfe, belonging to 

 at least more than one genus. They are very gigantic when contrasted 

 with the ordinary Algas of our existing seas ; nevertheless, some 

 approach to them in size is made in the huge and tree-like Lessonias 

 which Dr. Hooker found in the Antarctic seas, and which have stems 

 about twenty feet high, and with a diameter so great that they have 

 been collected by mariners in those regions for fuel, under the belief 

 that they were drift-wood. They are as thick as a man's thigh. 



NOTES AND MEMOEANDA. 



On Bleaching Diatomacese, &c. — Dr. E. L. Maddox sends us the 

 following valuable note : — The structure of the silicious valves of the 

 DiatomacesB, so largely engaging the attention of many microscopists — 

 though seldom before the entire destruction of the endochrome by 

 nitric acid or other agents — I beg to offer for their notice, from some 

 experiments conducted lately in bleaching both marine and fresh- 

 water forms, the use of chlorate of potash and hydrochloric acid as 

 likely to prove «er^ useful in the examination, not only of the skeleton, 

 but the disposition of the endochrome; and it seems probable the 

 same may be employed with success on the minute Algae and minute 

 forms of organic life commonly accompanying them in the collection. 

 The proportions used have been varied, but about 40 grains of the 

 crushed chlorate to 1^ drachm of the acid in 1 ounce of water, placed 

 in a 2 or 3 oimce phial, closed with a waxed cork, may be taken as 

 the average proportions : the action of the evolved chlorine com- 

 mences after a short period, and can be watched or modified as re- 

 quired. The use of this mixture for the examination of chitinous 

 structures in insects was advocated by Dr. Hicks ; but I am not aware 

 of its having been extended to the Diatomaeea) ; therefore the sug- 

 gestion is made in the hope it may be found useful by those engaged 

 in the examination of the organization of these very interesting 

 objects. 



