12 Journal of the Mitchell Society [Augnst 



Mai'chantiales Cliiloscyphus 



Eiccia Harpantlius 



Eeboulia Marsupella 



Aster ella Lejeuiiia 



Lunularia Jungermannia 



• Conocephalus Odontoscliisma 



Marehantia Calypogeia 



Jungermamiiales Anaerogynae Kantia 



Sphaerocarpus Bazzania 



Kiccardia Lepidozia 



Metzgeria Tiichoeolea 



Pallavicinia • Diplophyllum 



Pellia Scapania 



Fossombronia Eadula 



Jungennaiiniales Acrogynae Poiella 



Nardia Cololejeunia 



Jamesoniella FruUania 

 Plagioehila Anthocerotales 



Loplioeoleia Anthoeeros 



Cepholozia Notothylas 



Aspects of Constant Curvature. Archibald Henderson. 



In this paper, Dr. Henderson outlined a number of ways for de- 

 termining the value of the Gaussian eurvation on surfaces of constant 

 curvature. This was shown to be intimately associated with the ex- 

 pression for the linear element on the surface. Making use of two 

 forms given by Riemann for the linear element of a surface of con- 

 stant curvature, it was shown by appropriate examples how the curva- 

 ture could be singled out by inspection. Illustrations were given for 

 the sphere, written in three different ways, parametrically, and for 

 the pseudo-sphere as compared with the sphere of imaginary radius. 

 Attention was called to the fact that little had been done in this 

 direction ; and that there was room for the display of great ingenuity 

 in devising parametric representation of surfaces suitable for the 

 purpose of determining curvature. 



Physical Factors in the Artificial Incubation of Eggs. Charles INI. 

 Heck. 



A review of the research that has been done on the incubation of 

 eggs shows that temperature control, humidity regulation, and venti- 

 lation are involved in the following manner. Temperature control is 

 more important the longer the incubating temperature has been main- 

 tained, and commercial devices fullv meet the demands of this con- 



