42 [February, 



From my own observations at the University Laboratory, I was 

 unable to find any traces o£ ova or spermatozoa (except in one case, 

 where immature ova were found) in accordance with what we should 

 expect. It does not follow that the genital organs themselves need 

 be affected, but the germ cells that give rise to the germinal layers of 

 the sexual organs. From the observations I have made I gather the 

 following results : — 



I. — The ? Stylops gains its nourishment from host by osmosis, and this causes the 



alimentary canal, in part, to become abnormal. 

 II. — The abnormal canal is forced upon the sexual organs, and renders them in 



whole or part abortive. 

 III. — That the ova and spermatozoa are not generally present in infected imagos. 



Kingston-on-Thames : 



January, 1892. 



OYIPOSITION OF ADELA VIRIDELLA. 

 BY T. A. CHAPMAN, M.D., F.E.S. 



In May, 1890, I got several $ Adela viridella and confined them 

 on sprays of oak in blossom, with the result that six or eight eggs 

 w^ere laid by the moths in the petioles of the blossoms, but so that 

 half the egg was included and pinched in the incision made by the 

 moth, the other half protruding as a pearl-like bead outside. 



Although the analogy of Jihulella and rufimitella suggested inflo- 

 rescence as the necessary nidus, and the impression I had that oak 

 was the proper food was very strong, I felt it difficult to accept this 

 result as a normal one, and as a matter of fact all these eggs perished 

 without coming to anything. It was further pointed out to me by 

 Dr. "Wood that in the head-quarters of viridella in this district the 

 oaks rarely blossom or fruit, being undergrowth or very young trees. 



Last year, on June 3rd, Dr. Wood and myself visited the habitat 

 of viridella with a view to take a further step, if possible. It was 

 late in the afternoon before we reached the ground, and very dull, and 

 we saw hardly one ^ viridella on the wing. After sundry unsatisfactory 

 researches, we took to shaking certain young oak trees, say 4 or 5-in. 

 in diameter of stem, and 20-ft. high ; out of each of these usually 

 one or two $ viridella flew with a steady flight, and in a somewhat 

 downward direction, so that we each took home some eight or ten 

 specimens. They came usually from quite the tops of the trees ; only 

 a few (^s were disturbed by this process. 



