136 American Quarterly Microscopical Jouriial. 



order to cut well and evenly, must be carried through the sub- 

 stance to be cut, especially if it is soft, in a slanting direction, 

 so that each point of the edge describes a curve which is equal 

 to a part of a circle. By referring to Figs. 3 and 4, it will be 

 seen that in my apparatus this is exactly what takes place when 

 the knife is moved, the radius of the curve being the length of 

 the arms from the center of the clamps to the center of the 

 pivots. 



Another point of importance in cutting these sections is, 

 that the knife should always be wet with alcohol so as to pre- 

 vent the section from adhering to it. I find the simplest and 

 most economical method of preventing this adhesion to be the 

 wetting of the tissue, by means of a small camel's hair brush 

 dipped in alcohol. Sufficient alcohol remains on the surface 

 of the tissue to cause the section to float on the knife. 

 iyTo be continued.) 



OBSERVATIONS ON SEVERAL FORMS OF 

 SAPROLEGNIE^. 



BY FRANK ^. HINE, B. S. 



Concluded. 



ACHLYA. 



In April, 1877, when searching in a springy pool for Algae, 

 I found a pine twig {Finns strobus), which had the ends and 

 scars of the broken branches, where resin had exuded, sur- 

 rounded by a dense and very conspicuous cushion or ball-like 

 mass of radiating filaments ; the whole being white, with a 

 slightly grayish tint (PI. VI., Fig. i). The specimens, which 

 were just coming nicely into fruit through sexual reproduction, 

 were placed in a jar of water and allowed to remain with- 

 out change; but the filaments soon became so surrounded by In- 

 fusoria, Algae, and foreign matter, that they were rendered 

 unfit for examination. Others were then procured and the 

 water kept fresh, in which condition they grew and were 

 suitable for continuous study. 



The filaments were generally simple, but branches some- 

 times appeared in very limited numbers. They were similar 

 in structure to the filaments of the Saprolegnia already de- 

 scribed, being formed of a slightly granular protoplasm, 

 surrounded by a delicate wall of cellulose; as was shown 

 by its blue color with the iodine test. Their diameter was 



