6 MICROSCOPICAL RESEARCH 



have some knowledge of field and garden botany, and of natural 

 history generally. Day by day we see plants spring from the earth, 

 become bigger and bigger, and send out ramifications in every direction, 

 but how few stop to study the phenomena of their growth ; how does 

 the plant or animal grow is the question that the microscopist has to 

 answer; and herein lies the necessity for the use of chemical killing, 

 fixing, and preservative agents in microscopical investigations, so that 

 the dead tissues of plants and animals shall as nearly as possible 

 present to the observer their natural conditions as when in a living state ; 

 thus enabling the investigator to trace out all the varied changes that 

 take place during the life cycle of the plant or animal under 

 observation. 



Many methods have been devised for this purpose, among which 

 the following have proved efficient, and will answer for the killing, 

 fixing, and preservation of the specimens used to illustrate this work. 



Fig. I. — Collecting Case, containing six 3J in. x i^ in. tubes for fixatives. 



The most simple preservative is methylated spirits of 92 per cent, 

 in strength, into which may be placed immediately as collected, such 

 specimens as roots, stems, leaves, leaf or flower-buds, ovaries, seeds. 



