ZOOLOGY. 311 



ternal gill-like appendages. As to the origin of the trachea?, 

 Biitschli (1870) believed that their mode of origin was the 

 same as the silk-glands, and that the two sets of organs were 

 homologues, and that they were derived primitively from 

 the segmental organs of worms, which are arranged in pairs 

 along the body of the latter animals. In 1873, Packard sug- 

 gested that the air-tubes may have originated independently 

 within the body, and afterwards formed a connection with 

 minute pores leading through the skin. In 1 874, Semper ex- 

 pressed the same views as those of Biitschli, which in the 

 year after were accepted by Mayer. Moseley regarded them 

 in 1S74 as dermal glands modified. Packard then suggest- 

 ed that the tracheal system might be derived from the water 

 vascular system of certain low worms ; while, in a late pa- 

 per on the development of the Lepidoptera, Hatschek con- 

 ceives that the air-tubes are derived from respiratory por- 

 tions of the skin much enlarged. Finally, Palmen appears 

 to adopt the view that the trachea? may have originated 

 from the segmental organs of the jointed worms, which in 

 turn originated from the dermal excretory glands of the 

 lower unjointed worms. This shows how conjectural is our 

 knowledge of the origin of these interesting organs. He 

 conceives that the excretory function of the primitive lung- 

 sac was afterwards replaced by an absorbing function, and 

 the sac or tube became a respiratory organ viz., a trachea, 

 which (at first simple and sac-like, due originally to an in- 

 pushing of the skin) became longer and branched, until it 

 assumed the present form. With this view we should not 

 be disposed to find fault as a provisional hypothesis. 



Sir John Lubbock, in a fourth communication to the Lin- 

 nsean Society (reported in Nature) on the habits of bees and 

 wasps, illustrated by ingenious experiments his modus ope- 

 randi of testing their faculties, dispositions, habits, etc., by 

 something of a double F apparatus, whereby an interval of 

 three tenths of an inch, either by a drop from above or reach- 

 ing upwards the distance from below, alone prevented ants 

 from graining access to a covered glass all filled with larva?. 

 They evidently had not the acumen to surmount the three 

 tenths of open space, although they had for hours before been 

 traversing the route and carrying off larva? previous to the 

 small gap being made. Industry was conspicuously shown 



