CONSTITUTION OF MESOGLCEA OF ALCYONIUM DIGITATUM. 393 



The mesogloea does not contain gelatine. Hence also, it 

 cannot contain chondrin-like bodies. The popular term 

 '^ jelly" applied to this substance appears to have no basis in 

 chemical fact. 



(b) Does the mesogloea contain nucleo-albumen? The recog- 

 nition of this body in several non-cellular tissues suggests its 

 presence here. To test this point a colony was stripped of its 

 external layers and treated by Halliburton's method for extract- 

 ing nucleo-albumen.^ None could be detected. 



Thanks to the method recently introduced by Lilienfeld and 

 Monti/ the examination of this question micro-chemically is 

 also feasible. Specimens hardened in osraic acid were cut with 

 the freezing microtome, then washed thoroughly and placed 

 in a solution of ammonium molybdate. After being washed 

 for a few seconds in a mixture of ether (9 parts) and water 

 (1 part), they were put into a 20 per cent, ethereal solution of 

 pyrogallic acid. The cells in such specimens were seen under 

 the microscope to be stained black, but the mesogloea was not. 

 Hence we conclude — 



The mesogloea does not contain nucleo-albumen. 



V. Conclusions : 



(i) The mesogloea of Alcyonium digitatum is chiefly 

 composed of a hyalogen. 



(ii) Prior to the conversion of the hyalogen into hyalin the 

 mesogloea will yield a mucin. 



(iii) It also contains a small amount of an insoluble albu- 

 minoid body, whose nature was not determined. 



(iv) It does not contain gelatine or nucleo-albumen. 



1 Halliburtou, 'Brit. Assoc. Reports,' 1888 ; •Journal of Physiology,' 

 vol. xiii. 



2 Lilieufeld and Monti, ' Zeit. f. pliysiol. Cliem.,' Bd. xvii. See also 

 Gourlay, ' Journal of Pliysioiogy,' vol. xvi. 



