POLLEN 225 



In some genera, the cells open through round holes or 

 pores at the top (or bottom) of the anther. These pores 

 are very obvious in SOLANUM the Brinjal, Chilli, etc., 

 in RHODODENDRON and in some species of CASSIA. 



In two families the LAURINE^E and the BERBERI- 

 DE^E, there are holes on the sides of the anthers, 

 and these are covered by little flaps which open and 

 close like doors. 



THE POLLEN 



12. The pollen grains are formed, as was said above, 

 in sets of four, and when ripe fill the whole hollow 

 space of the anther, as a mass of tiny golden balls. 



In some species the pollen grains are smooth, in 

 others they are covered with small warts or spines, 

 and tend to stick together. It is a curious fact of which 

 we shall see the connexion further on, that in small 

 and inconspicuous and scentless flowers, like those of 

 grasses, Paddy, Ragi, etc., the pollen grains are smooth, 

 while in large showy flowers like Hibiscus they are 

 usually spiny or rough (see p. 234). 



In some species they are connected together in sets 

 of four, the sets in which they were formed. In 

 others again the sets all cohere together in one 

 mass, and when the anther opens come out as such. 

 This is the case in ALLAMANDA. There are two 

 -important families the ASCLEPIADACE^E, and the 

 ORCHIDACE^E, in which the pollen grains ; of each 

 anther cell are nearly always united into " a single 

 mass, which is then termed a pollinium. We shall 

 study these later on, when dealing with the plants 

 themselves (see Part II). 

 15 



