vin.] THE BEAN-PLANT. Bj 



a. Pollen-grains: small oval bodies, with pro- 

 jections on them in the equatorial region. 



d. The anther of a bean is so small that sections 

 cannot be made of it without considerable skill : 

 the structure of an anther can however be easily 

 made out by imbedding one from a tiger-lily in 

 paraffin or holding it between two bits of carrot, 

 cutting transverse sections, mounting in water 

 and examining with i inch obj. 



a. It contains four chambers, two on each side 

 of the continuation of the filament, and in 

 each chamber lie numerous pollen-grains. 



5. The pistil. 



a. It is found by tearing open the stamen-tube : it 

 is a long green tapering body, somewhat flat- 

 tened laterally and ending in a point (the style) 

 which bears a tuft of strong hairs. 



b. Slit it open carefully : in it lies a central cavity, 

 containing a number of small oval bodies, 1he 

 ovules, attached along its ventral side by short 

 pedicles. 



c. It is difficult to get a section of a bean-ovule, 

 but its essential structure may be readily made 

 out by making thin transverse sections of the 

 ovary of a large lily (where the ovules are 

 closely imbedded in a large quantity of paren- 

 chyma) and examining with i inch obj. 



a. The central cellular portion of the ovule 

 (nucleus] made up of a large number of cells. 



Its two coats, an inner (primine) and outer 

 (secundine). 



