and Laboratory Methods. 2191 



■^ 



CURRENT BOTANICAL LITERATURE. 



CHARLES J. CHAMBERLAIN, University of Chicago. 



Books for Review and Separates of Papers on Botanical Subjects should be Sent to Charles J. 

 Chamberlain, University of Chicago, Chicago, 111. 



Schtnid, B. Beitrage zur Embryo-Eniwicke- Several " pseudo monocotyledons," or 

 lungeitiiger Dicotyln. Bot. Zeit. 60: 207- dicotyls with only one cotyledon, are 

 230, pis. 8-10, 1902. -; . 



described by Schmid in a recent paper. 



In Ranunculus Ficaria the single cotyledon is at first lateral but gradually 

 becomes terminal, pushing the stem tip to one side so that it appears to be lat- 

 eral. There is scarcely a rudiment of the second cotyledon. In Buiiiuffi bulbo- 

 castanum also there is doubt as to whether a slight protuberance should be inter- 

 preted as a second cotyledon or not. In Cyclamen persicum the ripe seed shows 

 no trace of a second cotyledon. 



Attempts to induce the development of the missing cotyledon by removing 

 the prominent one, gave only negative results. 



With such technique as is often described to readers of the Journal it 

 would appear that many of the points here left in doubt might have been set- 

 tled, c. J. c. 



_,..,,„„ ^ , , „ It is particularly difficult to fix cells 



Timberlake, H. u. Development and Structure '■ ■' 



of the Swarm Spores of Hvdrodictyon. like those of Hydrodictyon on account 

 Trans, of Wisconsin Acad, of Sciences, Arts ^f ^^g t^ick wall, delicate layer of pro- 

 and Letters, 13 : 486-522, pis. 29-30, 1902. •' 



toplasm and large central vacuole. 



The following formulae gave very good results, not only for this alga but also for 



Vaucheria and Spirogyra : 



Merkel's Fluid,— 



1.4 per cent, solution of chromic acid - 25 c. c. 



1.4 per cent, solution of platinic chloride - 25 c. c. 



Eisen's Fluid, — 

 0.5 per cent, solution of iridium chloride in distilled water 100 parts. 

 Glacial acetic acid ------- 1 part. 



The following stronger solution was also used. 



1 per cent, iridium chloride in distilled water - 100 parts. 



Glacial acetic acid ------ 3 parts. 



It is unfortunate that the solutions are so expensive. Flemming's chromo- 

 osmo-acetic acid mixture and also solutions containing mercuric chloride were 

 unsatisfactory on account of the frequent distortion of the structure of proto- 

 plasm. The safranin-gentian violet-orange combination gave the most delicate 

 differentiation. Zimmerman's fuchsin-iodine green proved good for mitotic 

 figures, but was of little value for pyrenoids and other structures. 



The nucleus has a well defined nuclear membrane and a nucleolus. In the 

 arrangement of its chromatin it bears a further resemblance to the nucleus of the 

 higher plants. The spindle is bi-polar and at its tips are bodies which the writer 



