Literary Notices. 387 



also contains the finest plates we have seen of the appearance of 

 the Podura scale under various degrees of magnification, the Arach- 

 noidiscus Japenicus, some of the most beautiful Polycystina, the 

 so-called glands in deal, the Demodex jvlliculorum, and certain other 

 objects. It is not generally known that a simple split fragment of 

 a lucifer match offers, as Mr. Beck explains, the best and readiest 

 mode of examining the structure of deal, which is beautifully dis- 

 played under a two- thirds object-glass. One of the plates gives the 

 appearance of Norbert's lines as shown by an one-eighth, with the 

 third eye-piece of Messrs. Smith and Beck's series, magnifying, 

 1300 linear. As very few microscopists have had an opportunity 

 of seeing Mr. Norbert's wonderful ruling on glass, we may state 

 that his lines are arranged in twenty bands, varying in closeness 

 from a ratio of 13 to 70 in one thousandth of an inch. Mr. Beck 

 says that " an one-eighth of 120° aperture will show them all ; but 

 when cut down to 110° it will not separate the 20th band ; at 100° 

 the 17th (63 in 001") is the limit; at 80°, the 14th (57 in 001") ; 

 and at 60°, the 10th (45 in 001"). Thus it will be seen that these 

 lines afford excellent illustrations of the effect of varying angles of 

 aperture, and they are more reliable than diatom lines, because there 

 is not the same doubt as to their real degree of proximity, which 

 varies in different specimens of the same diatom. For testing the 

 excellence of correction, the Podura scale is the best object for high 

 power, and with Mr. Beck's plates and directions the merit of any 

 objective may be readily ascertained. 



On the Distribution of Rain over the British Isles during} 

 the Tear 1864, as observed at about 900 Stations in Great Britain 

 and Ireland. With illustrations. By G. J. Symons, Member of the 

 British and Scottish Meteorological Societies. (Stanford.) — The 

 increasing body of persons interested in meteorological inquiries 

 will welcome this laborious compilation, and Mr. Symons deserves 

 great credit for the zeal with which he has extended observations 

 on the rainfall of these islands. From explanations given by Mr. 

 Symons, it appears that up to 1864 he defrayed the entire expense 

 incidental to the collection of- rainfall statistics, and that about 

 £100 was contributed towards the expenses of that year. We cer- 

 tainly hope that some arrangement may be made by which the 

 future collection of these important facts will not be permitted to 

 throw upon Mr. Symons a loss of money as well as a great expen- 

 diture of time. 



Sea and River-side Rambles in Victoria: being a handbook 

 for those seeking recreation during the summer months. (Geelong, 

 Heath and Cordell ; London, Kirkland & Co.) — It is very pleasant 

 to find a cheap and prettily illustrated handbook of the popular 

 zoology and botany of Victoria. From the skill with which Mr. 

 Hannaford has performed his task, we cannot doubt that he will 

 induce many of our Australian friends to devote a little of their 

 leisure time to the pursuit of natural history, which will not only be 

 advantageous to themselves but useful to science ?> as their country is 

 rich in objects of great interest. 



VOL. VII. — NO. V. C C 



