90 The Microscope. 



Free intercellular nerve endings are due to the intercellular fibres 

 losing their cells with which they are connected, and such are, conse- 

 quently, most common between the superficial cells. — Journal R. M. 

 Society. 



Movements of Diatoms. — Mr. W. H. Shrubsole in The English 

 Mechanic says: "Although I have studied the living forms for years, 

 I am quite unable to account for the marvelous phenomenon. By 

 Prof. W. Smith it is referred to forces operating within each frus- 

 tube and originating in the vital operations of growth, which may 

 cause the surrounding fluid to be drawn through one set of aper- 

 tures and expelled through another. The existence of apertures is 

 clearly established, and is exemplified in the mineralized forms I 

 had the good fortune to find in the London clay ; but granting this, 

 if the motion be the result of aqueous cui'rents, how is it that one 

 does not see this outside the diatom ? If anyone with better appar- 

 atus than mine has seen small particles influenced by the supposed 

 endosmosis and exosmosis, I would be glad to receive information. 

 Some diatom motion that I have observed has been clearly attributa- 

 ble to the superior attractive force of an associated group lying near, 

 and I have sometimes thought that the molecular movements first 

 observed by Sir Eobert Brown in 1827 should be taken into account. 

 Still, as far as I know, the problem as to the active power has yet to 

 be solved. The movements certainly are wonderful, and when 

 watching the more active forms, it is hard to dispossess oneself of 

 the idea that they are sentient organisms. Especially is this the 

 case with Bacillaria paradoxa, which, being well-known, need not 

 be described. In conclusion, I would point out that the power of 

 motion seems to be largely dependent upon form. The discoidal 

 and triangular diatoms are generally, if not always, immobile: those 

 that are boat-shaped move fi-eely, and most active are those of linea 

 outline. I may briefly add that I have quite recently met with some 

 of these last-mentioned in London clay, all that I had previously 

 found in that formation having been either discoidal or triangular. 



Chlamydomyxa in the Engadine. — Dr. E. Ray Lankester, 

 writing to Nature, says that since Mr. Archer, of Dublin, published 

 his account of the protozbon to which he gave the name Chlamy- 

 domyxa, in the Quarterly Journal of Microscopical Science twelve 

 years ago, no one has been in a position to independently confirm 

 his description. While at Pontresina last August, Dr. Lankester 

 discovered a protozoon which he thinks belongs to Archers genus 



