108 The Irish Naturalist* May, 



less numbers ; but experiments with this pollen have shown 

 that when deposited on the stigma it emits no pollen-tubes, 

 and consequently the flowers are not truly hermaphrodite, but 

 only apparently so . . . their stigmas are not capable of 

 exciting the emission of pollen-tubes in the ripe pollen 

 deposited on them." In order to prove that the Holly is not 

 dioecious, it is necessary to show that pollen-grains from a 

 berry-bearing tree are capable of emitting pollen-tubes. This 

 can only be ascertained by experiment, but to this the Holly 

 lends itself in a singular manner. The blossoms are near the 

 ends of the twigs — they are axillary and almost, if not altogether, 

 sessile. Nothing could be easier than to cover a number of 

 these terminal twigs with gauze bags ; the leaves would keep 

 these at a sufficient distance from the blossoms to make the 

 visits of insects impossible. The bags should be put on before 

 the flowers open. It will then be impossible for these to 

 become fertilized, except by the pollen of blossoms from the 

 same twig, or by pollen artificially conveyed to them. When 

 the flowers are fully expanded, the bags should be removed for 

 the purpose of applying with a camel's-hair brush the pollen 

 from another berry-bearing tree, and the bags immediately 

 replaced. After an interval of a day or two the applied grains 

 should be carefully examined under the microscope, and if they 

 are found to have emitted pollen-tubes ; or, better still, if in the 

 autumn any of these flowers are found to form berries, we may 

 safely assert that the Holly is not dioecious. 



We must, however, be careful not to found too much upon 

 negative results. The Holly is, from some cause of which 

 I am ignorant, often a very shy fruiter. This is very 

 noticeable in the New Forest, where thousands of acres are 

 covered with Holly, forming as it does the natural underwood 

 of the Forest. Here occasional trees are laden with berries, 

 showing that from some source they must have received an 

 abundant supply of pollen, while their neighbours, for many 

 yards around, are but sparsely sprinkled with fruit. 



The statement of Smith that the earlier flowers are the least 

 perfect should be borne in mind by experimenters, the later 

 blooms being selected where practicable. I hope that careful 

 experiments may throw more light upon the subject. 



Millicent, Co. Kildare. 



