136 



PROCEEDINGS OF THE AMERICAN ACADEMY 



On motion of Mr. Henck, a special appropriation of two 

 hundred dollars was made, for the purchase by the Library 

 Committee of additional works upon mathematics, technol- 

 ogy, and engineering. 



On motion of Professor Agassiz, special meetings for sci- 

 entific discussion were voted to be held, at the hall of the 

 Academy, on the fourth Tuesday of February, March, and 

 April ensuing. 



Professor Peirce made a further communication upon the 

 tail of Comets, especially of Donati's Comet. 



Mr. H. J. Clark read the following paper upon the use 

 of the microscope, as recently improved, in the investiga- 

 tion of the minute organization of living bodies : — 



" I was incited to bring together my thoughts and experiences upon 

 this subject, by discovering, three or four months ago, a novel feature 

 in the so-called glandular dots of the wood of our common White Pine 

 {Pinus Strohus, Linn.). 



"A dot of this kind is usually represented by a circle (Fig. 1, C, d), 



in the centre of which is a single or 

 double ring (a, b), which has about 

 one third the diameter of the first 

 (d). The outer circle (d) is de- 

 scribed as the boundary of a len- 

 ticular space (A, e) between two 

 contiguous cells, and the inner double 

 circle (C, a, h) as the outskirts of 

 a perforation (A, a h) in the deposit 

 layer (/) of the cell. The double 

 circle arises, as is said, from the fact 

 that the perforation has the shape of 

 an extremely short truncate cone, 

 which, when viewed endwise, pre- 

 sents to the eye its two circular 

 ends concentrically ; the broader end, 

 which is always next the interior of 

 the cell, corresponding to the outer 

 (h), and the narrower end to tlie 



Fig. 1. 

 g^ d f ecba 



feg 



