CHAPTEPv VIII 



DISSECTION AND ANALYSIS OF THE FLOWER 



Apparatus Required; Microscopes. — For the thorough and convenient 

 examination of floral structure, it is desirable to employ both the 

 compound and the simple microscope, and it is better to use two forms 

 of the latter. The compound microscope for ordinary use should have 

 a focus of about li inches, and it should be provided with a strong 

 illumination for viewing opaque objects. The simple microscopes used 

 should be a dissecting microscope, having a magnifying power of 

 some 20 to 30 diameters and an ordinary jeweller's loup. It must not 

 be assumed, however, that all of these instruments, useful as they are, 

 are essential to the work. Excellent work in all directions can be 

 performed by the use of a strong loup alone, especially if it be held in 

 the eye or attached by means of a flat steel wire passing around the 

 head or inserted into a spectacle frame, so that both hands may be 

 free for the work of dissection. 



Other Apparatus. — ^The other apparatus required is a pair of pointed 

 forceps, a pair of stout needles inserted into thick wooden handles, and 

 a dissecting knife. 



Regular Order of Procedure. — ^It is well for the student in the examina- 

 tion of flowers to accustom himself to a definite order of procedure, as 

 the numerous points to be noted are thus far less likely to be forgotten 

 or overlooked than when considered in a disorderly manner. It is 

 furthermore highly desirable that the characters observed should be 

 written down in systematic sequence before the book is referred to. 

 The order of procedure is from without inward, or in other words, from 

 below upward. The anthotaxy should first be carefully examined and 

 the position of the flower with reference to others in the cluster noted, 

 as well as its position upon the stem and the direction in which it faces. 

 The position when in l)ud should be compared with that when in flower. 

 When flowers are aggregated in ,close clusters surrounded by involucres, 

 all the characters of the latter as a whole and of the bracts of which 

 they are composed, must be noted precisely the same as though we were 

 studying the calyx of a single flower. The receptacle upon which the 

 flowers are borne within the involucre must also be thoroughly examined 

 as to its size, form, and surface and the ])resence of bracts or scales 

 interposed among the flowers. 



