158 



THE AMERICAN MONTHLY 



[August, 



deed, we engaged passage by tele- 

 graph and sailed without due prepar- 

 ation, but not without regret for the 

 anticipated pleasures of the railroad 

 joiu-ney, and the friends we should 

 meet on the way. 



These notes will be posted at As- 

 pinwall . The incidents of the voyage 

 have not been numerous or of partic- 

 ular interest. The broken, lumpy 

 water of the Caribbean Sea made a 

 slight change in the ordinary course 

 of events, but as a whole the passage 

 has been a good one. 



The temperature in the tropics at 

 sea is not so high as might be antici- 

 pated. There has been no great dis- 

 comfort from the heat on the steamer, 

 for a good breeze has been blowing 

 almost constantly. One evening, as 

 we were watching the progress of a 

 rain storm to the eastward, a squall 

 of remarkably cool air came on quite 

 suddenly, and carried away a sail with 

 a great deal of flapping, that made 

 some excitement for the lady passen- 

 gers. Such cool and refreshing cur- 

 rents we have noticed quite frequently 

 within the tropics at sea, apparently 

 coming from a local shower not tin- 

 away. 



As we write now, about 300 miles 

 from Aspinwall, the sun is shining, 

 casting its shadows southward — for 

 its declination is well to the north of 

 us. Within five minutes the rain may 

 come down in torrents, and as quickly 

 the sky clear again. It is the rainy 

 season in this region, and if we suc- 

 ceed in crossing the Isthmus without 

 floating ofl' in a deluge, and escape 

 the attack of Dr. Freire's germs, to 

 say nothing of those as yet unknown 

 microbes of Chagres fever, our read- 

 ers will hear from us again next 

 month. 



Eyes of Insects. — In the Traiis- 

 acfiofis of the Linnean Society Mr. B. 

 Thompson Lowne, F. L. S., has an 

 article entitled, 'On the Compound 

 Vision and the Morphology of the Eye 

 in Insects,' in which the structure of 

 the eves of insects is described as 



made out by the author. His results 

 differ in important details from the 

 conclusions of all previous observers, 

 but there is strong evidence in sup- 

 port of them throughout the paper. 

 One reason for these differences is 

 unquestionablv to be found in the 

 improved methods of preparation. 

 For example, it was found that in the 

 ordinary process of preparing sec- 

 tions of eyes, a certain structure, 

 v^hich the author has found to be an 

 inner lens situated behind each cor- 

 neal facet, is entirely lost, and the 

 shrivelled stroma of the lens consti- 

 tutes wdiat has long been known 

 as the ' nuclei of Semper.' Further, 

 the true structure of the cornea or 

 basilar membrane has only been made 

 out by the study of extremely thin sec- 

 tions, such as have not hitherto been 

 made. 



According to these observations the 

 compound eye consists of two lenses, 

 the first forming an inverted image 

 which is magnified and erected by 

 the second, the image being thrown 

 upon a retinal surface composed of 

 structures resembling the rods and 

 cones of the vertebrate eve. 



Postal Ceub Boxes. — Box S~ 

 came to this circuit June lotli with 

 seven slides. 



1. Palate of garden snail. Thomas 

 Garth. 



2. Spicules of sea-fan, Gorgonia. 

 E. S. Coutant. A good sketch of 

 the sea -fan or 'flexible coral' is 

 given, with a description of the 

 method of obtaining the spicules. 



3. Section of cork oak. J. M. 

 Barrow. 



4. Medulla oblongata in myelitis. 

 G. W. Hubbard. 



5. Amphipleura pelkicida. Chas. 

 Mitchell. Picked specimen in bal- 

 sam. The same preparer sends an- 

 other slide showing sarcoma. The 

 method of mounting is described in 

 full. 



6. Diatoms from Puget's Sound, 

 Geo. W. Woraster ( .?) . 



Box A came to hand June loth. 



