TRANSACTIONS OF SECTION D. GO 5 



5. The Aj)j)earance of the Army Worm in the Provhice of Ontario during 

 1896. By Professor J. Hoyes Panton, M.A. 



The author gives in tliis paper the results of his observations iipon the army 

 worm (Leucania unipuncta) during tho summer of 1^90, -when it appeared lu 

 large numbers throughout Ontiuio. As it infested the fields at the Ontario Agri- 

 cultural College, he was favourably situated to collect much valuable information. 



A sketch accompanving the paper showed very distinctly the infested districts— 

 .39 counties and 118 townships. A number of experiments were conducted to 

 ascertain the principal food plants of this insect. The results showed that its food 

 is largely restricted to the GraminecB, and that it will not feed upon plants from 

 the Lc/uminoscb and other orders unless pressed by hunger. When no food was 

 given in twenty-four hours the insects began to devour one another. Many natural 

 enemies were found to prey upon this caterpillar, insectivorous birds, toads, pre- 

 daceous beeMes, and parasitic flies. The Tachina fly {Nemorma leiccanim) was one 

 of the principal insect foes that kept it in check. 



Beneath a windrow of green oats sprinkled with Paris green (a pound to 

 75 gallons of water) thousands of dead caterpillars lay. This was spread along the 

 irround so as to stop their march into the adjoining iield. 



Several artificial remedies were referred to, the chief being to plough a furrow 

 with its perj^endicular side next the field to be protected, or a ditch may be dug in 

 the same position. Holes dug at intervals of 10 to 15 feet in the furrow or ditch 

 will be useful in catching the worms which fail to climb the sides and wander 

 aimlessly along the furrow. The worms collected in the furrow or ditch may be 

 destroyed as follows :— (a) Ploughing a furrow so as to bury them ; {h) sprinkling 

 coal oil upon them ; (c) scattering straw over them and firing it ; (d) dragging a 

 heavy pole along the ditch. 



6. On a Supjjosed Nexv Insect Structure. 

 By Professor L. C. Miall, F.R.S. 



On llecapitulation in Development, as illustrated by the Life History 

 of the Jfasked Crab (Corystes). By ^Y. Garstang, M.A. 



8. On Muscido-glandular Cells in Amielids. 

 By Professor Gustave Gilson. 



TUESDAY, AUGUST 24. 



The following Papers were read : — 



1. On the Plankton collected continuously during a traverse of the Atlantic 

 in August 1897.1 By Professor W. A. Herdmax, F.B.S. 



Through the kindness of the owners and of the captain of the Allan liner 

 ' Parisian,' I was enabled to run sea-water through four silk tow-nets of djfi'erent de- 

 ^Tees of fineness continuously day and night during the voyage from Liverpool to 

 Quebec. I used two nets (a coarser inside a finer) on the port side, tied to a tap 

 through which about 3,600 gallons ran in twelve hours. On the starboard side the 

 two nets were attached to an overflow pipe, delivering about 21,600 gallons in 

 the twelve hours — six times as much as on the otlier side. The nets were 

 emptied and the contents examined morning and evening, so that each gathering 

 was approximately twelve hours' catch, and each day, and each night, of the voyage 



' This paper will be published in full in the Transactions of the Biological 

 Society of Liverpool during the session 1897-98, vol. xii., p. 33. 



