The Microscope. 91 



Chlamydomyxa, and which he says is extremely abundant in the 

 Swiss locaHty. He thus describes his observations of the specimens 

 secured, under the microscope: " But I found a number of yellowish 

 spheres, about y^ inch and less in diameter, tvhich excited my 

 suspicions. After a brief delay these beo^an to throw out proto- 

 plasmic filaments, and soon, around each, was a wonderful series of 

 branching stems of protoplasmic threads, reaching far away from 

 the central yellow granular body, and in the most varied directions. 

 Along the threads minute oval corpuscles slowly streamed. * * * 

 From what I have seen of Chlamydomyxa, I am now inclined to 

 admit that it is less closely related to Cienkowski's Labyrynthula 

 than is generally supposed. The moving corpuscles of Cienkowski's 

 organism are very much larger bodies than are the oval corpusles 

 of Chlamydomyxa." 



Microscopic Appearance of Glass after Passing of Induction 

 Discharge. — Two years ago, when making some experiments with a 

 laro-e induction coil, I found that when a thin microscopical cover 

 glass was placed between the secondary electrodes it was very 

 quickly pierced by the calorofic discharge. On looking at the glass 

 a small roughened spot was seen around the point where the dis- 

 charge had passed. When this is examined with the microscope (50 

 diameters and polariscopic attachment), small blue crosses are seen 

 over the field, and generally a few of larger size are to be made out. 

 Is there any theory in regard to the formation of the above, or are 

 they simply caused by air bubbles carried through the heated glass 

 by the force of the discharge ?— A. B. Northcote iu Egl. Mechanic. 



The Microscope in Mineralogy. — Prof. J. W. Judd writes as 

 follows: The recognition of certain characters in the rock-forming 

 minerals as being original and essential, and the distinction of such 

 from other characters which are secondary and accidental, is of the 

 highest importance to the petrographer and geologist, and not less 

 so to the mineralogist. Rightly studied, these minerals are capable 

 of furnishing the geologist with evidence not only concerning the 

 mode of origin of the rocks of which they form a pai-t, but also of 

 the changes which they have undergone since their first formation. 

 The study of the minerals included in the crystalline rocks is not 

 less important than that of fossils in the sedimentary rocks. And to 

 the mineralogist the study of this secondary characters of minerals, 

 and of the causes which have produced them, is equally necessary. 

 Kesearches of this kind, indeed, can scarcely fail in the end to 



