100 



THE AMERICAN MONTHLY 



[May, 1883. 



By the aid of the black-board some typ- 

 ical forms of pollen-grains were described. 

 There is great variety in form, and the 

 surface-markings not only add to their 

 beauty, but enable them to become readily 

 attached to insects which thus aid in cross- 

 fertilization by carrying the grains from 

 one plant to another. 



The pollen-grains, when they become 

 attached to the pistil, extend their envelope 

 in the form of a tube — the pollen-tube — 

 which makes its way through the tissues 

 of the style and stigma, down to the ovary, 

 where it discharges its fovillae, and fer- 

 tilizes the germ-cell of the future seed. 



The paper was very interesting through- 

 out. At its close there was some dis- 

 cussion as to the fact of the pollen-tubes 

 extending down as far as the ovary. Mr. 

 Britton thought there could be no question 

 that they did so. In one case he had 

 clearly observed it. 



A new form of microscope-table was 

 shown by Mr. Schrenk. The particular 

 feature of the table was a revolving centre 

 upon which the microscope is intended 

 to be placed. 



Ten different kinds of pollen-grains 

 were shown by members. 



At a meeting of the New York Micro- 

 scopical Society, April 6th, a lecture was 

 delivered on the subject of " Deep-sea 

 Sounding and Dredging." This lecture 

 was the first of two lectures to be delivered 

 on this subject, and was confined to a 

 description of the apparatus and methods 

 employed in deep-sea work. It was 

 illustrated by lantern transparencies, using 

 an oxyhydrogen lantern. 



NOTICES OF BOOKS. 



The International Scientists' Directory. 

 Containing the names, addresses, special 

 departments of study, etc., of amateur 

 and professional naturahsts, chemists, 

 physicists, astronomers, etc., etc., in 

 America, Europe, Asia, Africa, and 

 Oceanica. Compiled by Samuel E. 

 Cassino. Boston, U. S. A. : S. E. 

 Cassino and Company. 1883. {Pp.458). 



This valuable publication is out early 

 in the year, and is much more complete 

 than any of its predecessors. It contains 

 450 closely-printed pages, and for accuracy 

 it seems far more creditable than any 

 other directory we have seen. 



Tenth Annual Report of the Secretary 

 of the State Board of Health of the 

 State of Michigan, for the fiscal year 

 ending September 30, 1882. Lansing: 

 W. S. George &; Co., State Printers and 

 Binders. 1883. (Pp. 37 and 592). 



This Report contains some valuable 

 essays on special subjects, relative to 

 sanitary matters, such as ventilation, 

 plumbing, drainage, etc. 



Les Insectes Fossiles, specialment d'apres 

 les travaux de Sir Samuel Scudder. 

 Par Charles Maurice, Licenci(f es- 

 Sciences naturelles. Lille: Imprimerie 

 six-horemans 244, Rue Notre-Dame. 

 1882. (Pamphlet, pp. 32). 



We are indebted to the author for this 

 interesting brochure, the nature of which 

 is sufficiently explained by the title. It 

 is an extract from the Annates of the 

 Geological Society 01 the North. 



Excliansres. 



For Exchange. — Well-mounted double -stained vege- 

 table preparations, also, a few first-class injected prepar- 

 ations for other well-mounted slides. N. A. Richards, 

 St. Louis, Mich. 



Well-mounted slides of Polycystina, transparent and 

 opaque, for any well-mounted slide. P. C. Cole, M.D., 

 254 West Forty-second Street, New York, N. Y. 



Wanted. — Slides of Bacteria in exchange for other 

 slides, or for cash. J. M. Adams, Watertown, N. Y. 



Wanted. — I will give a good type slide of diatoms, 

 or a slide of arranged diatoms, for a gathering of Pleuro- 

 si^iita angidatum. Thos. Christian, loS Virginia St., 

 Richmond, Va. 



Diatomaceous Material and Histological slides 

 for other well-mounted and named slides of Foramini- 

 fera. Animal Parasites, Pathological subjects, etc. K. 

 Cauch, M.D., Carpenteria, Cal. 



Sections : Kitten's Jaw, teeth in situ, in exchange 



for first-class slides. Jay L. Smith, 86 Beekman St., 

 New York City. 



Fo siL Diatoms from Carson, Nev., and Posa Creek, 

 Cal., slides or material to exchange for good diatoms, 

 mounted or material. Also, many other diatoms; lists 

 exchanged. The above deposits are rich and newly di,>i- 

 covered by myself. F. H. Engels, M.D., Virginia, Nev. 



For Slides of Diatoms from the Wabash & Erie 

 Canal at Ft. Wayne, send any well-mounted slide to 

 H. C. Tresselt, Fort Wayne, Ind. 



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