AN HOUR AT THE MICROSCOPE. 140 



the present paper, but may perhaps claim notice in a future 

 number. 



The operation called " floating," which has been described in 

 these papers, was first made known by Professor Williamson, in his 

 Monograph on British Foraminifera (Ray Society), which contains 

 excellent figures and descriptions of most of our species, and is 

 still the text-book. 



For students, Dr. Carpenter's " Introduction to the Foramin- 

 ifera" (Ray Society), also his papers in the Philosophical Transac- 

 tions ; a paper by Parker and Jones in Philosophical Transactions, 

 on the Foraminifera of the North Atlantic ; and various papers in 

 Annals of Natural History Magazine, by Dr. H. J. Carter and 

 others, will all be found full of valuable and interesting 

 information. 



Charles Elcock. 

 Belfast. 



an 1bour at tbe flDicroecope, 



Mttb /ilM% ITuffen Mest, ff.X.S., 3F.lR.m3., zic. 



Plates 13, 14, and 15. 



Fimaria hygrometrica. — The peristome of this Moss fur- 

 nishes an exquisite object for the microscope. 



In mounting, it is desirable to show one peristome, at least, 

 looked directly down upon, and one in exact profile ; while ano- 

 ther in section, to show the columella, would add much to the 

 value of such a slide. The one lateral seta developed on the 

 inner side, and near the point of each tooth of the peristome, is 

 highly interesting ; as is also the delicately reticulate, cancellous 

 membrane in the centre of each mouth. The section suggested 

 would also show the set of sixteen inner peristomial teeth, on 

 which one of the characters of the genus is based. 



Petal of Geranium. — The structure is one which is not 

 uncommon in petals, — an elevation of the centre of the cuticular 

 cells (mostly of the upper — />., inner series) into papillae, the 

 delicate furrows on vv'hich are often exceedingly elegant. When 

 these papillae have still further developed, they then form hairs. 

 The Periwinkle, Primrose or Polyanthus, Garden Balsam, Snap- 



