DIRECTIONS FOR lA BORA TORY STUDY. 389 



gium ; (/>) microspores lodged about the mouth of integument, the 

 spermary often forming a tube. (*f, 3S6.) 



Examine a 2-3'ear-old (mature) cone. Observe 



14. The extreme woodiness of the cone, especially the carpels 

 which are spread apart when dry. (1\ 404.) 



15. On the upper surface of some carpels, two thin wing-like 

 scales, with a jcci/ attached. 



16. Time the fall of winged seed from the extreme height to 

 which you can reach. Time its fall after removing wing. How 

 will this aid in distributing seed ? (1[ 492.) 



Bisect a seed lengthwise, parallel to flatter faces. Observe 



17. The firm seed-coat, which is the integument of the ovule 

 grown and ripened. 



18. Enclosed by the coat a white tissue loaded with starch and 

 oil, the endosperm, which is the enlarged female gametophyte. In 

 the center of this the embryo sporophyte which grew from one of 

 the eggs produced by the female gametophyte, after the egg was 

 fertilized. Note that the tissues of the sporangium have disap- 

 peared, having been crowded and absorbed. (^ 403.) 



19. Dissect out the embryo from another seed. Observe that 

 it is already differentiated into a slender ji'fw, and six /rz'marj' 

 leaves about its apex. (Fig. 339.) 



B. MARSH MARIGOLD (Caltha palustris). 



1. Examine the roots. Observe (a) their surface, wrinkled 

 from shortening; (b) their structure. 



2. Cut a transverse section as in fern; observe that mechanical 

 tissues are wanting. 



3. Bisect longitudinally the base of a plant. Observe, as shown 

 by the origin of leaves, the variable length of internodes; at 

 base the internodes are very short so that leaves are crowded; 

 in the middle the internodes are long and leaves distant; above, 

 the internodes become shorter until, in the flower, they are not 

 developed and the leaves are very much crowded. (T^ 119.) 



Study one of the well developed foliage leaves (1 150). Ob- 

 serve 



4. The broad rounded blade with slight branches (teeth) at the 

 margin. 



5. The long slender stalk, petiole, gradually passing into 



