736 JOURNAL, BOMBAY NATURAL HISTORY SOCIETY, Vol. XIX 



at the bottom of the water among the mud and debris and rarely comes to the 

 surface to breathe. It has a well developed tracheal system but there are 

 uo open stigmata on the body surface showing that water carries the air 

 through their walls. The walls of the rectum have many folds, around the 

 membrane of these are small tracheal tubes which communicate with two main 

 trachea running longitudinally through the body one for each side. A number 

 of tubes branch from these penetrating every part of the body bringing the 

 whole tracheal system into direct communication with the water cavity of the 

 abdomen. Water is taken in by means of the rectum and the oxygen contained 

 in it passes in solution through the walls of this cavity. The oxygen passes 

 through the tracheal vessels in every part of the bodj^, and through the rectum 

 is expelled the waste products in the form of carbonic acid gas. At the hinder 

 end of the body of certain dragon fly larvte (aqrionidcc') are three thin leaf -like 

 plates. These appendages are respiratory as well as being organs of locomotion. 

 These larvas breathe by dissolved oxygen conveyed to the body by means of 

 these plates which, when microscopically examined, are found to be covered 

 with very fine tracheal tubes. The pupa> of dragon flies differ very little from 

 the larvae and are quite as active. The larva3 of dragon flies have a peculiar 

 arrangement for the capture of their prey known as the " mask " which is in 

 reality a modification of the labium or lip. This " mask "• so called because it 

 covers the front of the head consists of two parts. When not in use the "mask " 

 is folded up, the broad portion spreading over the mouth, and the other part 

 bent backwards between the front limbs. When the larva wishes to feed 

 (all dragon fly larvae are highly carnivorous) this mask arrangement is shot 

 suddenly out and the prey captured by the pseudo-jaws. The mask is then 

 retracted bringing the food to the mouth. I may mention here that both 

 dragon flies,and their larvas are extremely tenacious of life. A larva I procured 

 of the family LihelluUdm for the purpose of dissection was thrown into nearly 

 boiling water and removed after half a minute and appeared quite dead 

 when first taken out but eventually recovered and lived for some time after. 

 I once caught some dragon flies of the same family and after first disabling 

 them by a pinch on the thorax placed them in a box with a strong solution of 

 ammonia, and found they still retained signs of life two hours after. Dragon 

 flies have extremely small antennae, indeed these organs being merely rudimen- 

 tary. This is made up to them however by their large and well developed 

 eyes. Large antenna to such creatures of wild and rapid flight would, I 

 should imagine, be more of a hinderance than a help to their owners. The 

 laying of eggs of dragon flies varies in the different species. Some enter right 

 under the water for the purpose of doing so, others again alight on the surface 

 cf the water. I watched a large LibeUula depositing its eggs which was 

 effected in the following manner : — The insect hovered closely over the water 

 and bent the abdomen so that the tip nearly touched the under-part of the 

 thorax, then with a succession of jerks the eggs were laid one after another. 

 The water was too deep to allow me to wade in and see whether the eggs 



