518 HOMES WITHOUT HANDS. 



Some oak-galls may be called compound galls. M. Bosc men- 

 tions a small gall which is found upon the American oak. It is 

 not larger than a pea, and if shaken is found to contain some 

 hard substance loosely lodged in its interior. When the gall is 

 cut open, a very curious state of things is seen. The walls are 

 very thin, so that, in spite of the small dimensions, the cell is 

 larger than that of many Cynipidas. Within the cell no insect 

 is discovered, but in its place a little spherical object, about as 

 large as a No. 5 shot, which is very hard, and rolls about freely 

 in the interior. If this be opened, the larva is found within it, 

 reminding the adept in fairy lore of the white cat whose gifts 

 were inclosed in a succession of nuts, each, within the other. How 

 these singular little cellules are made is not known, though their 

 discoverer expended great trouble and patience upon them. 



The same naturalist mentions another species of gall, also found 

 upon the oak in Carolina. It is spherical, covered with prickles 

 like a thistle, and beset with, a thick downy covering of rather 

 long hair. Many other galls possess these characteristics, but the 

 most curious point connected with this species is that the hairs 

 are as mobile as those of the sensitive plant, and, as soon as they 

 are touched, sink down, and never afterward regain their former 

 position. 



There is a kind of fungus which is found in wine-vaults, and 

 which exhibits a similar phenomenon. When newly grown it 

 hangs in great masses, like tufts of pure cotton wool. But to 

 carry a specimen away is impossible, for, as soon as it is touched, 

 it begins to contract, and in a minute or two shrivels up into a 

 flat membranous mass, that looks like the web of the house-spider. 

 M. Bosc was unable to rear any of the inmates of these galls. 



The size of a gall is no criterion of the dimensions or numbers 

 of the insect which made it. Even in the galls which infest the 

 oak, the smallest galls often furnish the largest insects, and in 

 some specimens brought from Greece, the gall is as large as an 

 ordinary black currant, while the cell would contain a red cur- 

 rant, showing that the inhabitant of the cell must be a large one 

 in order to fill it. Again, although the oak apple and rose bede- 

 guar do contain a great number of insects, there are many exam- 

 ples where galls scarcely as large as a pea contain from ten to fif- 

 teen insects, while the ink gall and the large Hungarian gall are 

 inhabited by a single insect. 



