6 MEETINGS. 



for the more perfect safe-guarding of the spiracles, and that is their 

 position. In the perfect insects they are often concealed and always 

 protected in some way. Mr. Marquand described the respiratory 

 apparatus of the common gnat larva, and alluded to some other 

 curious forms of aquatic insect life, and then went on to describe the 

 airtubes or trachea by means of which the air is distributed through- 

 out the entire system. The larva of Dytiscus (the great water- 

 beetle) affords an example of the typical respiratory system of insects. 

 These air vessels extend throughout the entire body ; they are distri- 

 buted through every organ, and accompany the most minute nerves 

 through their whole course. By a simple mechanism familiar to 

 everyone in the flexible gas pipe of our houses — namely, the winding 

 of a loose spiral thread within a stout elastic outer membrane — the 

 tube is always kept distended. In some insects, especially those 

 adapted for powerful flight the trachea are dilated at intervals into 

 oblong vesicles or sacs which form reservoirs of air; but no such 

 sac-like expansions occur in grubs or larva?, nor in insects that 

 constantly reside on the ground. 



Mr. A. Collenette contributed a paper on " October, the 

 wettest month of the year in Guernsey," being the result of 

 observations made and recorded during the past forty-seven 

 years, first by the late Dr. Hoskins, and latterly by Mr. 

 Collenette himself. To avoid reading out a vast number of 

 figures, and at the same time to appeal more forcibly to his 

 hearers through the medium of the eye, Mr. Collenette had 

 prepared with great skill an elaborate chart, which showed at 

 a glance the various points to which the lecturer wished 

 attention directed. 



An animated conversation naturally followed the reading 

 of each paper, and a hearty vote of thanks was accorded 

 to the gentlemen who had contributed them. 



Monthly Meeting held December 10th, 1889, Mr. H. Grousaz 



in the chair. 



There was a very good attendance of members, and 

 several visitors. The Rev. G. Robins and Mr. J. Mourant, 

 jun., were unanimously elected members of the Society, and 

 Miss M. B. Collings, Miss B. Carre, Mrs. Noble, and Mr. F. G. 

 Taylor were proposed for election at the next meeting. 



Mr. C. De La Mare read the first part of a paper on 

 " The correlation and relative age of the rocks of the Channel 

 Islands." 



In this he dealt at some length with the gneiss and 

 diorite, which he considered had been proved to belong to the 



