464 



MY GARDEN. 



by which it can pierce the trunks of pine-trees, and it has been 

 known to gnaw through leaden bullets. I have not seen it in my 



garden, though in other places 

 it has been known to be 

 highly destructive. Th e figure 

 is from the excellent book of 

 Kolliker, translated by West- 

 wood, and represents S. gigas 

 (fig. 1027). 



Gall-insects are another ex- 

 tensive section of the Hymen- 

 optera. The species which 

 develops the nutgall {Cynips 

 Fia .027— Sirex gigas. Hqiikola, fig. I028), which is 



used in the manufacture of writing ink, has within the last fifteen years 

 spread throughout England, and exists in my garden, especially in the 

 lower branthes of the oak, or on the low oak bushe.s. The oak-apple 

 {C. terminalis, fig. 1028a) carried by some good people on King 

 Charles's Day (the 29th of May) is caused by the larvae of another 



Fig. 1028.— Gall on Oak. 



Fig. 1028a.— Cynips terminalis. 



Fig. io2g.^Redbreast's 

 Pincushion. 



hymenopterous gall-insect ; whilst the mossy excrescence on the rose 

 {Rhoditis rosece, fig. 1029) is another example of the effects of this 

 section of hymenopterous insects. All theSe excrescences are detri- 

 mental to the plant on which they live, and should be removed. 



4nts exist in my garden, but they do us little or no harm, although 

 they sometimes locate themselves in our glass-houses. There are species 



