DIRECTIONS FOR LABORATORY STUDY. 387 



7. Numerous small spores, the microstores. Microsporangia are 

 usually at tip or base of spike and are often difficult to find if 

 material is not collected at proper season. (^[1J 326, 327.) 



V. SPERMATOPHYTES.* 



A. PINE (Pinus sylvestris). 



Examine a shoot showing at least the growth of present year 

 and that of the preceding. Observe 



1. Two kinds of axes : (a) the main axis of the shoot, with un- 

 limited growth, now terminated by a conical bud ; (I)) the very 

 short lateral axes of limited growth, dwarf branches, each bear- 

 ing two needle-leaves. (^[ no, fig. 101.) 



2. The six forms of leaves. Study the shape and structure of 

 each, (a) the slender green leaves, needles ; (b) the scales closely 

 covering the older parts of the stem, in whose axils arise the 

 dwarf branches carrying the needle-leaves ; (c) the thin broad 

 scales on the dwarf branches, enwrapping the bases of the needle- 

 leaves (best seen about the leaves on the young shoot) ; (d) the 

 scales protecting the apical bud (^[ 160) ; (e) the two forms of 

 sporangium-bearing leaves, sporophylls, in the two sorts of flowers 

 (see further 4 and 9). 



3. Dissect the scales carefully from a large terminal bud and 

 compare the interior parts with those of the shoot which bears it. 

 Can you make out the corresponding members? If not, it is 

 because the bud is too young. Use a bud taken from the tree in 

 summer or autumn and these points can be seen best. What is a 

 bud? (p. 85.) 



4. Examine the sporophylls. Observe the two kinds : (a) 

 Numerous oval clusters of yellowish bodies, the micro sporophylls 

 or stamens, about the base of the young shoots (fig. 101), now 

 called a staminate flower ; (b*) a single cluster of mega-sporophylls 

 about the apex of one or two short lateral branches arising just 

 below terminal bud of a young shoot and extending a little beyond 

 it, forming the pistillate flower. (HIT 331, 344.) 



5. Study the arrangement of the staminate flowers on the axis. 

 Compare the position of each cluster of sporophylls (flower) with 



* In this group the sporophytes only can be studied without the compound microscope. 

 For gametophytes see demonstration 



