San Francisco Microscopical Society. 21^ 



Seventy-two of the number of the species identified, he con- 

 siders as probable ancestral forms, identical with those now liv- 

 ing; among these are the California Redwood; two species of 

 American Poplars, and Swamp Cypress, together with other trees 

 now found living in China. Australia, Canary Islands, Europe, 

 and other countries. 



Lorenzo G. Yates, 



SAN LRANCISCO MICROSCOPICAL SOCIETY. 



October 26th, 1SS7. 



A letter was read from A. H. Rreckenfeld of Los Angeles, ex- 

 . pressing continued interest in the work of the society, and sending 

 a specimen of marine diatoms on seaweed from Professor Romyn 

 Hitchcock. The material was collected at Sakai, Japan. 



Dr. Ferrer continued his demonstrations of new accessories, of 

 which a part was given at the last meeting of the society. He 

 had just received from Zeiss of Jena a number of low-power ob- 

 jectives and oculars. These are apochromatic and are made of 

 the new glass the invention of which excited so much interest a 

 year or so ago. Beside the lenses for ordinary use to the mi- 

 croscope Dr. Ferrer exhibited projecting eye-pieces which are in- 

 serted in place of the ordinary eye-pieces when the instrument is 

 used in connection with a micro-camera for photographing. Dr. 

 Ferrer said he had but just received the glasses and not fully 

 tried them, but in his preliminary tests of their powers he was 

 convinced of their wonderful definition. Comparative examina- 

 tions were made of the Zeiss ordinary eye-piece and the ''compen- 

 sating eye-piece," which occupied the members for a long time 

 and afforded much material tor discussion. 



The society received several donations of material intrinsically 

 valuable and still more to be prized because of its associations. 

 'Moeller's typen platte' and 'probe platte,' a number of valuable 

 micro-photographs and a large collection of slides were received as 

 a gift from Mrs. W. Ashburner through Mr. Norris. They had 

 been part of the collection of the late Professor W. Ashburner 

 and will be cherished by the society which held him in such high 

 esteem. There was also a donation by Mr. Norris of a number 

 of slides and prepared diatomaceous material, and upon motion 

 of Dr. Selfridge the thanks of the society were extended to Mrs. 

 Ashburner and Mr. Norris for their generous gifts. 



Mr. Norris exhibited a slide mounted by Bourgoyne of Paris, 

 which contained 215 distinct varieties of diatoms from the famous 

 Santa Monica earth, all arranged in beautiful form. This slide 

 was presented by Bourgoyne to Professor Ashburner. 



Edward J. Unckson, Recording Sec'y. 



