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wonderful transformed vegetable products on account of their 

 symmetry, or regularity of form. They are produced by a 

 minute, almost microscopic, insect lodging itself at the apex of 

 an embryo-bud, either of a lateral, or terminal branchlet, flower, 

 or seed vessel, and these grow around and over the insect in a 

 fixed form, according to each species, instead of assuming simply 

 an abortive form of their original habit, as in so many cases of 

 other gall-forming insects. Each terminates one of the axes of 

 the hostplant, be these twig, leaf, flower-bud, or young seed- 

 vessel, and each contains only one of the originators in the 

 genera Brachyscelis, Sphaerococciis, Cylindricoccus and Frenchia 

 (the three last established by Mr. W. M. Maskell, but their 

 position left undetermined, Trans. N.Z. Inst., 1891), while in 

 Opisthoscelis and Ascelis they are formed by the bulging out of 

 the foliolar epidermis on one or both sides, and the space surround- 

 ing the insect filled by spongy, endodermic tissues. 



The originating insects themselves (i.e., within the same genus), 

 as already remarked by Schrader, present such slight differences 

 that they are almost unavailable for identiflcation, and the work- 

 ing out of the causes producing the varied result in respect of 

 the species will no doubt provide some future biologist with some 

 most interesting study. 



All Brachyscelid galls have a small or even minute opening 

 or aperture at or near the centre of their summit, or exceptionally 

 in the base. This communicates by means of a narrow channel 

 of various lengths with an oval, oblong or cylindrical cavity, 

 whicli is either more or less completely fllled by the occupant, or 

 more or less in excess of its size, and then usually more or less 

 occupied by a fluffy, waxy exudation. The galls of the two sexes 

 are widely differing in form and size. The male galls are always 

 s^ery much smaller, more or less elongated, forming cylindrical or 

 conical tubes, and are either on the leaves, young twigs, or 

 (rarely) on the female galls, occurring either singly, distantly 

 scattered, in crowded clusters, or irregularly. The perfect male 

 insect is described as being very minute, ranging from one-eighth 

 of an inch to one-sixth, furnished with a pair of wings, perfect 

 legs and antenna:', and two long anal setae, or fine hairs. They 

 have only been observed in a few species (no South Australian), 

 and of some species even the male galls are still unknown. 



The female galls, on the contrary, are mostly of very much 

 larger size, of definite form for each species, and either placed 

 singly on branchlets or forming crowded clusters on their termi- 

 nations. In the latter case the galls are usually more or less 

 distorted. A characteristic specific difference appears to be 

 exhibited in the direction of the axis of the gall — -that is, whether 

 more or less vertical, lateral, or dependent. It seems self-evident 



