376 SUMMARY OF CURRENT RESEARCHES RELATING TO 



break when the related structures do. Hereditary changes and modifica- 

 tions due to stimulation (e.g. high temperature) during ontogeny are in 

 the same direction. Laws governing the mechanism are the same 

 throughout. Orthogenesis is illustrated, but all the ontogenetic changes 

 cannot be said to illustrate recapitulation of phylogeny. During onto- 

 geny some species pass through colour-stages corresponding to geographic 

 races, but the biogenetic law of recapitulation is of doubtful application. 

 The brilliant colours are due to thin surface films of material having 

 properties of metals. Changes in colour during ontogeny are from 

 green and blue toward red or brown, except in Gicmdela lepida, where it 

 is from yellow (gold) to green. The centre of distribution is about the- 

 Indian Ocean. Experimental modifications nearly duplicate certain 

 geographic races in conditions similar to those in the experiment. The 

 more brilliant colours are in warm arid localities. J. A. T. 



Leaf-eating Crane-fly.— A. E. Cameron {Ann. Entomol. Soc. 

 America, 191H, 11, 67-89, 18 figs.). An account is given of the life- 

 history of Gylindrotoma splendens Doane from Vancouver Island, which 

 is peculiar in that the larvae feed openly on Bryophytic and Spermato- 

 phytic plants. The female cuts a slit in the epidermis on the under 

 side of the leaf by means of her saw-toothed ovipositor. The sub- 

 translucent glistening white eggs are partially concealed. The period 

 of incubation is two to three weeks. The newly hatched larvte eat 

 holes in the leaves ; their movements suggest those of " looper " cater- 

 pillars ; they hibernate among dead leaves in their second stage ; they 

 resume feeding in spring ; they pupate in the middle of May ; the pupal 

 period lasts for six ta ten days ; there are at least three moults before 

 pupation, one before and two after hibernation. J. A. T. 



Viability of Mosquito-eggs. — A. Bacot {Parasitology, 1918, 10, 

 280-3). Eggs of Stegomyia fasciata may remain dormant out of water, 

 but in humid atmosphere, for fifteen months, and develop thereafter. 

 Immersed eggs remained dormant for five months, but the limit is 

 probably about a year. J, A. T. 



The Pear Thrips.— A. E. Cameron and R. C. Treherne {Bidl. 

 Dept. Ayric. Canada, 1918, 15, 1-51, 22 figs.). Blighting of fruit-trees 

 in Vancouver Island is often due to Taeniothrips inconsequetis, the life- 

 history of which is discussed. An account is given of the egg, the larva, 

 the prepupa, the pupa, and the adult. The duration of the adult's life 

 in natural conditions is probably about four to six weeks. The mature 

 larvaj migrate from tree to soil, the adults migrate from soil to tree. A 

 careful account of the ovipositor and of oviposition is given. No male 

 has been seen in America, but a solitary specimen was found byCollinge 

 in England. Parthenogenesis is thus the normal mode of reproduction. 

 Unlike parthenogenetic Phasmids and Aphids, the Pear Thrips produces 

 only one generation in the year. J. A. T. 



Rectal Tracheation of Dragon-fly Larva. — Anna M. Cullen 

 {Froc. Acad. Nat. Sci. Philadelphia, 1918, 75-81, 2 figs.). In the larva 

 of Aryia putrida there s^'^m to be two areas of respiration in the hind- 



