The AtiCROSCOPE, 147 



(C.) Take a scraping from the roof of a frog's mouth and 

 examine in salt solution. The slide should be slightly warmed. 

 The cilia on these cells can be seen in active motion. Study this 

 motion carefully. 



(D.) Scrape the tongue of the frog and examine in the usual 

 way. These cells are columnar: rather long and thick. The nuclei 

 can be developed by adding a drop of acetic acid. 



(E.) Take a scraping from the freshly-cut surface of a liver ; 

 tease out in the salt solution and examine. These cells are polyhe- 

 dral in form. They are highly granular, from the presence, prob- 

 ably, of an animal starch, and contain normally small fat globules. 

 They contain fi'om 1-3 nuclei, which are round and well defined, 

 and seem to possess a delicate, structureless membrane. 



(F.) Other organs should be cut and scraped and the cellular 

 elements examined in the manner as above described. 



EDITORIAL. 



AX 7lTHIN the last few years a great advance has been made 

 ^ ' towards the pefection of the microtome. This advance has 

 enabled the microscopist to do work which before was impossible. 

 The writer was much impressed with this in looking over a collection 

 of specimens made in his student days, a collection in which he took 

 not a little pride. The majority of the sections were cut by hand 

 after having been embedded, though not infiltrated with parafiin. 

 The others were cut with a very primitive microtome. Very soft 

 tissues, as lung, myxomata, etc., were treated very summarily. Too 

 soft to be embedded, the art of infiltration unknown, they were 

 simply squeezed with the fingers between two pieces of amyloid 

 liver (a large supply of such liver being kept in a keg in the labora- 

 tory for the purpose) and cut by hand. With such methods the 

 results could be anything but perfect. And yet the writer would not 

 exchange many of the specimens thus manufactured with others 

 made by good mounters of the present day, not because of any 

 associations connected with them, but because they are better 

 specimens. They are not so smooth, for occasionally the knife was 

 " see- sawed " and left its trace. They are not so large, for to keep 

 up a sustained, steady motion was impossible. But they at least 

 have the merit of being moderately thick. 



It seems to be the aim of many possessors of good microtomes 



