2096 Journal of Applied Microscopy 



CURRENT BOTANICAL LITERATURE. 



CHARLES J. CHAMBERLAIN, University of Chicago. 



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

 Chamberlain, University of Chicago, Chicago, 111. 



Dixon, H. H. Sectioning witiiout Imbedding. Attention is called to the fact that 

 Notes from til e Botanical School of Trinity „. . . ,. , 



College, Dublin. No. 5, August, 1902. paraffin sections are often unsatisfac- 



tory where complexes of lignified and 

 delicate walls are to be prepared. Free hand sections, while often good over 

 small areas, are seldom good as a whole, especially if the object be large. 

 Professor Dixon recommends the microtome for cutting vegetable material 

 which has not been embedded. Soft material, like leaves and herbaceous stems, 

 should be left in alcohol to harden for at least a few days. Harder tissues, after 

 a few days immersion in alcohol, should be placed in a mixture of alcohol and 

 glycerine, adding more glycerine the harder the specimen. The material is 

 clamped in the microtome, and kept wet with glycerine and alcohol during the 

 cutting. The knife should be placed obliquely as in cutting celloidin sections. 

 For transverse sections of stems, roots, etc., the object is easily fastened, but it 

 is rather difificult to make longitudinal sections of small, cylindrical organs. 



Sections as thin as 10 /i may be cut in this manner. Wood of Finns sylvestris 

 (White Pine), after treatment with equal parts of alcohol and glycerine, gives 

 excellent sections by this method. If sections of the entire stem, showing both 

 wood and bast are desired, about two parts of alcohol to one of glycerine is a 

 better mixture. 



It is hard to make complete sections of monocotyl stems, like Zea Mais, on 

 account of the mixture of very soft and very hard tissue. Material, after treat- 

 ment with 90 per cent, alcohol and " a trace of glycerine," yielded excellent 

 sections 10-12// thick. 



Although this method of section cutting is subject to very definite limitations, 

 it is extremely useful where it can be applied. c. j. c. 



Note. — In the reviewer's laboratory, complete transverse sections of the 

 stem of Zamia have been cut without embedding. Some of the sections, two 

 and one-half inches in diameter, are not more than 20 /< in thickness. The 

 specimens were fastened into the microtome by means of an improvised clamp, 

 and the knife was placed obliquely as for celloidin sectioning. 



Murbeck, Sv. Ueber Anomalien im Baue gj^^^g parthenogenesis in the flowering 

 des Nucellus und des tnibryo-sackes bei r o o 



parthenogenetischen Arten der Gattung plants has been proven in only three 

 Alchemilla. Lunds Universitets Arsskrift. genQrd.—Antennariahy]ue\,A/chemilla 

 38: i-ii, pi. I, 1901. ° . 



by Murbeck, and in Thalictritm by 



Overton — it is interesting to note any accessory peculiarities. The most im- 

 portant observation is that the number of chromosomes remains unchanged 

 throughout the entire life history, not showing any reduced number in the 

 gametophyte stage. The behavior of the antipodal nuclei and synergids is also 



