HISTOLOGICAL METHODS. 235 



nuclear division or similar studies, balsam mounts are usually 

 preferable. 



It is sometimes found necessary in sectioning very small 

 and delicate organs to embed them in some firm substance 

 which, will permit sectioning, but these processes are too diffi- 

 cult and complicated to be described here. 



The following books of reference may be recommended. 

 This list is, of course, not exhaustive, but includes those works 

 which will probably be of most value to the general student. 



1. GOEBEL. Outlines of Morphology and Classification. 



2. SACHS. Physiology of Plants. 



3. DE BARY. Comparative Anatomy of Ferns and Phane- 



rogams. 



4. DE BABY. Morphology and Biology of Fungi, Mycetozoa, 



and Bacteria. 



These four works are translations from the German, 

 and take the place of Sachs's Text-book of Botany, a very 

 admirable work published first about twenty years ago, 

 and now somewhat antiquated. Together they constitute 

 a fairly exhaustive treatise on general botany. New 

 York, McMillan & Co. 



5. GRAY. Structural Botany. New York, Ivison & Co. 



6. GOODALE. Physiological Botany. New York, Ivison & Co. 



These two books cover somewhat the same ground as 

 1 and 2, but are much less exhaustive. 

 5. STRASBURGER. Das Botanische Practicum. Jena. 



Where the student reads German, the original is to be 

 preferred, as it is much more complete than the transla- 

 tions, which are made from an abridgment of the original 

 work. This book and the next (7 and 8) are laboratory 

 manuals, and are largely devoted to methods of work. 



