CATKINS 



help to make clear. The pollen grains are there 

 shown, to the left, magnified loo diameters ; or to 

 put it more simply, they there appear 10,000 times 

 as large as they really are. Again, on the right, 

 some of the grains are shown magnified 300 

 diameters, or 90,000 times their actual size. 



Having seen, then, how extremely tiny is each 

 of these pollen grains, we are better able to realise 

 that, when we shake the bough of the hazel bush 

 and cause a yellow cloud of pollen to be dispersed, 

 the cloud does not consist merely of thousands of 

 pollen grains, but of many millions. 



In view of this, it is not surprising that the 

 rosy stigmas protruding from the female, bud-like 

 catkins should receive some of the pollen from the 

 atmosphere. I have selected at random from a 

 hazel branch one of these catkins, taking care 

 while gathering it not to shake upon it any pollen 

 from the catkins on the same branch. In Fig. 36 

 (Plate 23) a magnified view of this catkin is shown, 

 and it is particularly interesting owing to the fact 

 that the pollen seems to have adhered to the 

 stigma only on the sides that face in one direction ; 

 and the side of the catkin itself that faces the same 

 way is also dotted over with the tiny, pale-yellow 

 grains. These details, together with the fact that 

 the grains are thinly scattered, all point to the 

 conclusion that the pollen visible had slowly 

 accumulated from a given direction ; most probably 

 carried by the wind or, it may be, by falling 

 showers in regular succession from the catkins of 

 the branches near by. 



53 



