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 PEOGRESS OF MICEOSCOPICAL SCIENCE. 



Metamorphoses of Siredon Mexicanus. — Professor E. D. Cope has a 

 short but interesting paper on this subject in Silliman's ' American 

 Journal ' for February. He states that Professor Baircl was well 

 acquainted with the metamorphoses of this group at the time that they 

 were observed in the Jardin des Plantes. Even so early as 1847, in 

 his essay, he regarded several species as larvfe. He, after some general 

 observations, records his belief that S. Mexicanus will be found to 

 undergo metamorphoses sometimes, but he states that he has not 

 observed it. 



Insects in Deep Salt-ieafer. — Mr. A. S. Packard, jun., gives in the 

 above-named journal a notice of certain insects obtained from deep sea- 

 water by Professor Verrill. Some of them are microscopic, and it is 

 puzzling enough to imagine how air-breathing animals obtain air at 

 20 fathoms depth in salt water. The author says the present species 

 was dredged by Professor Verrill in 20 fathoms, on Clark's Ledge, in 

 Eastport Harbour. It was found (four or five specimens, young and 

 adult) " on hydroids," &c. It will be an interesting point to determine 

 whether, like the other species of the genus, it also lives in the earlier 

 or even in the adult state among the giUs of Lamellibranchs, and also 

 whether it lives between tide marks, thus agreeing with the distribu- 

 tion of Chironomus oceanicus. At any rate we have here an insect and 

 a mite breathing by trachoc^, and extracting the oxygen from the water 

 at the great depth of 120 feet, and, in the case of the dipterous larva, 

 with no apparent variation from specimens living at low-water mark. 

 In this connection he notices the fact that they have on the New England 

 and Labrador shores several species of mites of the family Trom- 

 bididag, which run over seaweeds and live under stones between tide 

 marks, and he has observed similar species at Beaufort, N.C., and 

 Key West, Florida. As regards the distribution of the species of 

 brine insects, several questions of interest arise. How are we to 

 account for the origin of the Ephjdra lialophila in such prodigious 

 quantities in the vats of the Equality Salt Works of Illinois, a locality 

 remote from salt lakes and the ocean shores ? Are the brine species 

 of the Salt Lakes of Utah and California remnants of an oceanic 

 faima and of the tertiary period, or are they of recent and local 

 origin? Have these brine insects acquired their singular tastes 

 within a recent geological period (say the Quaternary), having lived 

 at first as do their allied species, in foul fresh-water, or amid decaying 

 matter in damp localities '? Before these and other questions can be 

 answered, we must have analyses of the waters, and a review of the 

 European literature on the subject, and larger collections of brine 

 animals from our own country. 



Infusoria and Sponges. — It does not at first appear that there is a 

 relationship of an intimate nature between these two. Professor H. 

 James-Clark, of the Kentucky University, appears to think differently 

 however, and imagines that there is an intimate relationship between 



