ZOOLOGY AND BOTANY, MICKOSCOPY, ETC. 211 



dealt with — annular light produced by a reflecting- condenser used in 

 conjunction with an oil-immersion objective for resolving fine structure 

 on diatoms and displaying stained bacteria. The Leitz concentric 

 reflecting condenser was the form used, and the results obtained when 

 resolving fine structure in diatoms were very striking. T. A. O'Donohoe : 

 ■• An Attempt to resolve Pinnularia nobilis." A series of lantern-slides 

 were shown of photomicrographs of this diatom with varying illumina- 

 tions, all of which failed to resolve it until the reflecting condenser 

 above described was brought into use. 



A very successful conversazione was held at King's College on 

 February 10, about 500 members and visitors being present. 



The 48th Annual General Meeting was held on February 24. The 

 Presidential address was delivered by Prof. Dendy, who spoke on 

 " Organisms and Origins." The extraordinary theories held even by 

 leading men of science in the early part of the eighteenth century, 

 relating to the nature and origin of fossils, were briefly dealt with. 

 Spontaneous generation was considered, especially with reference to the 

 recently published results of Dr. Charlton Bastian. The President said 

 that these results to a certain extent are in accord with purely a priori 

 expectations, but in other respects they appear improbable to the last 

 degree, especially with regard to the claimed production of such com- 

 paratively highly organized forms as a Penicillium producing spores in 

 the ordinary way. 



B. Technique.* 

 (1) Collecting- Objects, including- Culture Processes. 



Collection and Preservation of Hydroida.f — Generally speaking, 

 says G. T. Harris, a shore strewn with large fucus-covered boulders, 

 interspersed with rock-pools, indicates a good collecting ground, though 

 even on such a shore the hydroid life may be curiously confined to a 

 limited area. Clear limpid rock-pools are not necessarily indicative of 

 hydroids, and they may often occur in abundance in muddy pools, where 

 they are with great difficulty caught sight of. The easiest and best way 

 of working a rock-pool is, as was pointed out by T. Hincks, to lie at full 

 length on a mackintosh sheet with shoulders and arms projecting over the 

 pool. Pools heavily draped with fucus afford the best chance of success, 

 the sea-weed being turned back so as to expose the sides of the pool . 

 The finer species of seaweed are very remunerative if taken home and 

 looked over under a low-power of the Microscope. Small shells should 

 be carefully examined if encrusted with marine growth, and also the 

 carapaces of rock-pool dwelling crabs. • Dredging is more especially the 

 work of the professional naturalist ; when undertaken by the amateur a 

 small dredge and moderate depths will offer the best chance of success, 



% This subdivision contains (1) Collecting Objects, including Culture Pro- 

 cesses ; (2) Preparing Objects ; (3) Cutting, including Embedding and Microtomes ; 

 (4) Staining and Injecting ; (5) Mounting, including slides, preservative fluids, etc. ; 

 (6) Miscellaneous. 



t Journ. Quekett Micv. Club, xii. (1913) pp. 143-54. , 



