532 



less complete loss of colour in most stained preparations. Paro- 

 lein is absolutely neutral, and, so far as is known at present, is 

 entirely without action on any dyes. Further, it has a lower 

 refractive index than Canada balsam 1*471 as against 1*530 of 

 balsam in xylol. The following preparations, mounted in parolein, 

 were exhibited under microscopes very kindly lent by Messrs. 

 H. F. Angus and Co.: (1) Pernicious anaemia, Giemsa stain; 

 (2) Spirochaete and Bacillus fusiforme of Vincent's angina ; 

 {3) Spirachaeta pallida ; (4) Trypanosomes of Surra. 



The President said he also had had bad experience of Canada 

 balsam. In the case of a number of mounts of calcareous sponge 

 spicules, in some the spicules had been completely dissolved away ; 

 in others, mounted as long ago as 189G, no change at all had 

 taken place. Some samples of balsam become acid very rapidly ; 

 others, apparently, not at all. He had noticed similar trouble in 

 haematoxylin-stained preparations. The action was first noticed 

 at the edge of the cover-glass, and gradually spread inwards. But, 

 again, in other preparations, similarly stained and mounted, there 

 had been no fading at all, and, in certain instances, even a slight 

 darkening. He was very pleased to hear of a new mounting 

 medium of such promise. 



The President said he also had to thank Messrs. Ansfus & Co. 

 for the loan of the microscopes used to exhibit the preparations he 

 had brought down to the meeting. He had for the last year been 

 studying Try2Kinosoma lewisi in rat- fleas. He had had occasion 

 to dissect many rat-fleas, and sometimes got out the organs very 

 nicely. The salivary glands were very important from his own 

 point of work, and one of the preparations exhibited was of the 

 salivary glands of the i-at-flea. The system has first a common 

 opening in the proboscis, then a short tube branching in two, as 

 a Y-piece, of thin calibre, and with quite smooth cbitinous walls. 

 The branches of the Y lead right and left inside the body, and the 

 tube becomes slightly thicker, and looks something like trachea, 

 but is more or less irregular. The irregularities are most apparent 

 when the fresh preparation is examined in salt solution. The two 

 branches run back through the thorax to the abdomen, and, 

 branching again, end in little pouch-like bodies, which are very 

 ditficult to stain. Altogether, there are four salivary glands in 

 the body of the rat-flea. The President said his first dissection of 

 insects was of the tsetse fly, in Africa. Most insects have the 



