410 



EM^:Rr;ENCH: OP DRAGONFLY-LARV^, 



Text-tiji.4. "■ 



doiLuiicarrh, and .still coutiiiuc to li\e. Yet such was the case, 



and the final result, which 

 I have depicted in Text- 

 fi,ijf. 4, is botli ludicrous 

 and pathetic. The mature 

 embryo emerged as a pro- 

 nymph " tail- foremost," 

 until it finally became 



caught in the egg-shell, and died while still only partially free I 



Section 5. — Rectal Respiratioit in newly-hatched Zygopterid larva'. 



In November, 1915, a large number of eggs of a counnon 

 Zygopterid dragonfly (probably Austrolestes leda Selys, but not 

 determined with certainty) were found in the tissues of a reed 

 at National Park. These were kept hi fiitu in the reed, in water 

 in a Peti'i dish. Some of them were parasitised by a small 

 Hymenopterous insect new to science. The majority, however, 

 hatched out about a week after they were taken. No attempt 

 was made to observe the actual process of hatching in this case. 

 The principal object which I had in mind was the examination 

 of the caudal gills and tracheal system of the young larva-. The 

 eggs were examined several times a day. Consequently, a num- 

 ber of freshly hatched specimens, ranging from a few minutes up 

 to two hours old, and all of them perfectly transparent, came 

 under mv observation. 



The most striking discovery about these lar\;i> was that, fiuiu 

 the time of hatching onward for half-an-hour or more, rrijidar 

 rectal respiratioti icas carried on ivith yrcat vigour. The action 

 is exactly like that observed in the young lar\a of Ana.r. The 

 rectal cavity is alternately expanded and contracted, so thai 

 water is drawn in and expelled (juite regularly. No true fraclH-al 

 gills are to be seen, such as are visible from the first in the 

 rectum of Ana,c; but there are two, slightly opaque, longitudinal 

 folds, placed latero-ventrally, and evidently carrying a thickened 



"■' Abiiunnal hatching of pionymph P" of Anax papiitnsi-s Burm., " tail- 

 foi-emost"" ( x3U). 



