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Report on Botany. 



of these could be considered a true gall maker. He there- 

 fore very justly concludes that the excrescences are not of 

 insect origin, but of tungoid origin ; and this conclusion, 

 we may add, is entirely in accordance with our own view 

 of this subject. Our reasons for adopting this view are 

 briefly these. 



1st. The excrescence itself is similar in structure to other 

 excrescences which are known to be of fungoid origin and 

 at the same time it is quite dissimilar to most insect galls 

 produced in twigs and young branches. 



2d. The time of its development is opposed to the proba- 

 bility of its insect origin. We are well aware that our 

 knowledge of insect galls is extremely limited, and that 

 bere we are treading on dangerous ground and may here- 

 after be obliged in our turn to apologize to the entomolo- 

 gists, but so far as our observations extend, insect galls are 

 developed in the warmer seasons of the year, i. e. in spring 

 summer and possibly early autumn. Those that continue 

 to be the domicil of the young insect during the winter 

 are, so far as we have observed, fully grown in autumn, 

 and do not increase in size the following spring, a character 

 which does not hold good in the case of black knot. 



3d. The fungus is always present with the excrescence, 

 and its mycelium may be detected even in the earliest 

 manifestation of the tumor, and this fungus is never found 

 apart from the black knot. To our minds this alone is a 

 sufficient argument for our belief in the fungoid origin of 

 the excrescence. Who ever heard of any undoubted insect 

 gall being always accompanied and inhabited by a fungus ? 

 On the other hand the larvas of insects are not always present 

 in the excrescence, and of those insects that have been bred 

 from it, none, we are told, have been true gall makers. It 

 is true, members of the Cynips family are gall makers, and 

 the learned Schweiuitz constantly associated a Cynips with 

 his descriptions of this fungus, but then he did not affirm 



