14$ WAKE-ROBIN. 



iii. A roughened or hairy surface on the inner and 

 upper part of each style, the stigma. Note whether 

 any microspores (pollen-grains) are attached to the 

 stigma. 



2. That the parts of the flower arise from the end of a stem 

 which is broadened to form the receptacle. 



3. That all other parts are placed below the pistil, that is, they 

 are hypogynous. 



4. That each cycle is made up of a definite number of organs. 



5. That the members of one cycle of floral organs alternate 

 in position with the members of the succeeding cycle. 



6. Sketch an entire flower, then one member from each set 

 of organs that compose it. 



MINUTE STRUCTURE. 

 I. THE ROOT. 



In a central longitudinal section through a root-tip observe 

 the following regions: * 



1. The outer looser cells and the inner more compact tissues 

 forming the root-cap. This is disconnected from the root 

 except at the foremost portion. 



2. In the center of the section and immediately under the end 

 of the root-cap, a group of small angular cells, the primary 

 meristem, corresponding to the apical cell in the fern-root. 

 These constitute the region of most active cell-formation. 



3. Originating in the primary meristem are regions that 

 finally form the permanent tissues of the root. They are: 

 a. The dermatogen, an outer layer of cells on the root proper, 



beneath the root-cap. This layer later becomes the 

 epidermis, though it is not easy to distinguish it as such, 

 since it is probably a transient structure in the root. 



1 As it is difficult to secure uninjured tips of Trillium, an onion partly 

 submerged in water for a few days will supply substitutes that are even 

 better. 



