232 



On motion of Dr. Durkee, seconded by Mr. J. H. Abbot, 

 it was 



Voted, That a copy of the remarks of Mr. Bouve and 

 Dr. Jackson be communicated with the resolution of con- 

 dolence to the widow of Dr. Gay. 



Prof. Agassiz stated, that in his recent study of the Me- 

 dusae he had been able to make out a distinct muscular 

 structure. 



It consists of three systems of fibres, one superficial, which 

 had been never before observed, just under the epidermis, the 

 others more deeply seated. The external layer is made up of 

 circular and vertical bands of fibres, surrounding the whole mass 

 like the net of a balloon, and capable by their contraction of 

 changing its shape and reducing its size. The vertical bundles 

 alternating with the radiating tubes are by far the strongest. 

 The fibres upon the inner surface of the disk are disposed in 

 two layers, one of circular, and the other of vertical fibres. 

 The former lines the cavity, and the latter is situated between 

 the circulating tubes. By the contraction of these last, the 

 eye-specks can be moved. In the transverse partition of the 

 animal a circular and radiating set of muscular fibres can be 

 made out, the latter assisting in moving the eye-specks. Prof. 

 Agassiz mentioned, that he had also completed the study of 

 the nervous system in Medusce. He had found a continuous 

 nervous thread extending from one eye-speck to another. 

 These organs present a closer analogy to the organs of vision 

 in the higher animals than had been generally supposed. In 

 their structure some of them united in clusters closely resemble 

 a vertical section of the compound eyes of insects, and probably 

 are capable of receiving an impression of light and darkness if 

 not of distinct images. Prof. Agassiz stated that his observa- 

 tions of the muscular system of Medusae were made on them 

 when in the state of contraction immediately after death. 

 During life the movements are too active to permit close ex- 

 amination. He exhibited part of a series of engravings illus- 

 trating their structure. 



Dr. C. T. Jackson read analyses of three samples of 

 White Cast Iron, containing manganese. 



