58 ENTOMOLOGICAL SOCIETY OF ONTARIO. 



is unique ; they breathe with their intestines. The large intestine is covered with numer- 

 ous tracheae, and when the animal wisht=!s to breathe it opens the orifice of the intestine 

 and admits a quantity of water. This, of course, contains air mechanically suspended 

 which is taken up by the tracheae just mentioned." In expelling the water just taken 

 into the intestine, it is sent out with consideraV)le force, which propels the animal for- 

 ward with a jerk, several times the length of its own body ; by this means it keeps out 

 of the way of its enemies. 



Dragon-flies are the most harmless creatures in existence, utterly incapable of in- 

 juring man or beast, but, on the contrary, highly beneficial in all stages, inasmuch 

 as they are the natural enemies of the mosquitoes, house-flies, moths, and other nox- 

 ious insects, which would abound in greater numbers and interfere much more seri- 

 ously with our comfoi-t and our products than they do under the continuous and 

 effective check of the dragon-fly. Yet, strange to say, thpse insects are not known 

 by five-tenths of the people of Canada, and most of those who know them by name 

 are not acquainted with their habits, but — to quote from a previous article on the sub- 

 ject — " Avoid or destroy them on account of the mistaken impression which some 

 people have as to the poisonous efiect of their sting, or the childish tradition as to 

 their habit of sewing up the eyes and then stinging their victim to death." Others 

 admire them for their beautiful colour^ slender forms and graceful motions. 



They are known by various names and epithets, such as : Devil's darning-needles^ 

 mosquito-hawks, horse-stingers and some others in English. The Germans call them 

 Wasser-jung-fern, or virgins of the water. The Indian knows them by the name of 

 Kow-ne-she, or Duch-kow-ne-she, and the French are pleased to style them Demoiselles. 

 The last does not seem so appropriate as some of the other appellations, as the points in 

 which any of these creatures resembles a lady, are not clearly defined, unless it be in 

 their slender waists. I know that some of the large ants are called Demoiselles by the 

 French, and their delicate forms rather suggest the name, but with all their admiration 

 for the beauty and modesty of women, I agree with Duncan when he says: "No 

 Frenchman would think of comparing a dragon-fly with a lady, if the nature of this 

 animal was known " In this part of Canada dragon-flies begin to issue from their 

 pupa cases about the midlle of May, the first appearing are those of the genus 

 Libellula, and by the 10th of June all the diflerent species may be found on the 

 wing. After the middle of September they gradually disappear, but some of the 

 hardy species, ^\xc\v ai& Diplax hudsonka &ndi Aeschna vert icalis a.Ta.dvenosa, may be seen 

 well on in November, a|)paiently as vigorous as they were on starting out, and 

 hungry enough to devour the elements. 



It is interesting to know that even at this late date the Odonata is beginning to 

 assert its personality, and the services so long rendered by this family of insects are now 

 being observed, acknowledged and appreciated, not only by naturalists, but by many who 

 do not pretend to make a study of the subject, as the following will show : A few years 

 ago, while engaged in building the Lake Superior and Mississippi Railway, Dr. R. H. 

 Lamborn, of New York City, had occasion to make frequent excursions, in the capacity 

 of director and treasurer of the company, through the swampy forests around the head of 

 the great lake, and his experience with the mosquito and other troublesome flies of that 

 region was so impressive that he determined to array his own with all other natural forces 

 against them. Having observed the activity of the dragon fly in the destruction of the 

 mosquito, and also having witnessed an entomologist feeding a dragon fly that had eaten 

 thirty house-flies in rapid succession, without lessening its voracity, the thought came to 

 him that the artifical multiplication of the dragon fly might accomplish a mitigation of the 

 mosquito and house-fly pests. He accordingly sought among entomological works for 

 some account of experiments tending to throw some light upon the subject, but without 

 the desired result. Finding that science had left those investigations almost untouched, 

 and that there was nothing in the known life history of the dragon fly that would enable 

 him to form an opinion as to the possible success of such an undertaking, he addressed 

 letters to Dr. Uhler, of Baltimore, the highest American authority in the great class of 

 insects to which the dragonfly belongs, and Rev. Dr. McCook, another naturalist of high 

 standing, and having received the greatest encouragement from both of those gentlemen^ 



