78 



properly labelled. He said that on one occasion, near 

 Toulon, he observed a large number of P. brassicce pupae on 

 a wall facing the sun, at a time very near to their period of 

 emergence. On revisiting the spot a few days subsequently, 

 there having been in the interval showers of cold driving 

 rain, succeeded by a sharp frost, he found every individual 

 pupa, without exception, rotten. Mr. Tutt remarked that 

 no doubt this was because their vitality was not sufficiently 

 low to withstand such climatic severities as they had done 

 in the depth of winter. Mr. Carrington suggested that the 

 molecular action causing this disintegration of the pupal 

 tissue was due to the rupture of the vessels, owing to alter- 

 nate contraction from the extreme cold, and expansion, more 

 or less sudden, from the daily increasing heat of the spring 

 sun. This action was comparable to the bursting of the 

 cellular tissues of plants when killed by frost. Mr. Adkin 

 said that he had always found sudden changes of climatic 

 conditions extremely fatal. Mr. Carrington observed that 

 many hybernating larvae were but little affected by extreme 

 cold. 



Mr. F. N. Clark exhibited specimens of Psoroptes longiros- 

 tris, described by Megnin (Paris), an acarid parasitic on the 

 horse, ox, sheep, and rabbit. The example was from the 

 latter animal. 



Mr. R. Adkin exhibited a wasps' nest of several cells 

 found in a "hand" of tobacco from Kentucky. It was 

 made of mud, and no doubt the inhabitants were killed 

 during the process of drying the tobacco over wood fires. 



Mr. Montgomery exhibited numerous coloured drawings 

 of the eggs and first stages of the larvse of several species of 

 British butterflies. 



April i3tk, 1899. 



Mr. A. Harrison, F.L.S., F.E.S., President, in the Chair. 



Mr. B. H. Crabtree, F.E.S., Levenshulme, Manchester, 

 was elected a member. 



Mr. Edwards exhibited male and female specimens of 

 Dytiscus pnnctulatus taken at St. Ives, Cornwall. 



Mr. Scourfield then gave an interesting description of the 

 group " Entomostraca,'" illustrating his remarks by diagrams, 

 blackboard sketches, and examples under the microscopes 

 kindly furnished by members and friends (see page 28). 



