OF EPPING FOREST. 283 



Andvicus albopuuctata, A. malpighii, A. collaris and A. seminationis 

 are easily passed over. On the other hand, some galls, such as 

 Nenroterus haccavum and N . tricolor, being very difficult to preserve, 

 look so different in a collection compared with those growing 

 on the tree that previous examination of specimens in a collection 

 may be quite misleading to the beginner. When searching for 

 galls the casual examination of a branch is not sufficient ; a mimate 

 examination of buds, leaves, or cuttings, may often result in the 

 finding of several galls even when previous search has failed to 

 reveal their presence. So far as my experience goes, galls are 

 usually scarce in damp woods, and I have frequently found that 

 both species and specimens are more numerous in drier and more 

 exposed situations. One is often able to obtain better results in 

 a short time from searching hedges in a country lane than by 

 spending hours in searching trees in a wood. 



Expevimental Breeding. 



In order to ascertain the life-history of the various 

 species of gall insects, and to investigate the gall forma- 

 tions in the different generations, it is necessary that very 

 close and accurate observations should be made. The act 

 of oviposition is a very important item in this respect. In 

 all cases it is best, and in many instances essential, that in 

 experimental breeding the natural surroundings should be 

 maintained, in order to obtain satisfactory results. For those 

 insects which lay their eggs in the buds, the latter should be 

 well developed ; while for those which oviposit on the leaves there 

 should always be tender shoots ready for use. In order to effect 

 this a number of young oak saplings (about 4 or 5 years old) 

 should be obtained. They should then be planted in large pots 

 and placed in some sheltered position where they can obtain the 

 necessary amount of air and light and where they may be subjected 

 to the ordinary temperatures. At the same time the insects must 

 not be allowed to escape or get mixed up in any way. P'or this 

 purpose 1 have foimd the most satisfactory method to be one on 

 the same principle as that made use of, I think, by Dr. Adler. 

 A square box frame-work fitted with a glass top and having the 

 sides covered wiih gauze to give ready access to the air is placed 

 over each oak sapling. In some cases, in order to facilitate 

 observation, I had gauze on three sides only, the fourth side 

 being fitted with glass. In this way the insects are not allowed 



