510 PROCEEDINGS OF THE AMERICAN ACADEMY 



dry, still stretched upon the neck of the bottle. In drying, the tendinous 

 fibres seem to shrink together, causing a dilatation of the spaces between 

 them, in consequence of which the extravasated fluid is sucked onwards 

 into the finest lymph spaces. In this way two, three, or even four 

 layers of lymph spaces lying between as many different layers of ten- 

 dinous fibres may be clearly demonstrated. The dried fascia may be 

 mounted in Canada balsam between glass plates. The accompanying 

 drawing by Dr. Quincy represents the appearance of the fascia under a 

 low magnifying power. 



Mr. E. N. Horsford read the following paper upon the 

 Cause of the Columnar Structure of Decaying Ice : — 



It is a familiar fact that ice on lakes and rivers frequently assumes, 

 in melting, a peculiar honeycomb structure. It has been more espe- 

 cially remarked in the spring, by persons whose residences or pursuits 

 have brougbt them in contact with the phenomena of the sudden dis- 

 appearance of ice that but a short time before was thick and apparently 

 sound.* When blocks of solid ice have been thrown on the shore of a 

 lake or river, they more strikingly exhibit, after a few days of sunshine 

 and a temperature above that of freezing, a structure in which the 

 whole mass of ice seems resolved into closely set groups of irregular 

 prisms, in the main perpendicular to the original horizontal surface. 



This mass frequently retains for a long time its nearly full dimen- 

 sions, while steadily lessening in weight, from the solution of the walls 

 of what may be called the inter-columnar spaces, until at last the co- 

 hesion between the columns is overcome by gravity or slight agitation, 

 and what remains falls to pieces, a pile of long, slender, angular rods. 

 The diameter of these rods or irregular prisms is sometimes more than 

 an inch, and it is sometimes less than that of a knitting-needle. 



The same change frequently takes place in ice afloat, and when far 

 advanced the ice columns may be thrust down by the foot, leaving a 

 sharp, vertical wall around the space through which the foot has 

 passed. 



It has also been observed that where straw or litter has been dis- 



* Rev. Zadock Thompson, " Silliman's Journal," Vol. XII. 2d Series, 1851, p. 23. 

 General Totten, chief of the engineers of the United States Army, Amer. Assoc. 

 Adv. Science, Report for 1851. "Silliman's Journal," 2d Series, Vol. XXVIII. 

 p. 359. 



