18 Mr. H. J. Carter on the Anatomy 



to me like a new form of spicule; hence I mention the 

 fact. The horny sheath or part of the fibre remains ; but 

 the spicules of the core almost entirely disappear. 



Barcode. 



The sarcode of sponges may be generally defined to be the 

 pulp-like part in which all the rest of the structures are not 

 only imbedded, but from the original slime of which all have 

 been developed, and is analogous to the soft parts of other 

 beings, filling up the insterstices of and enclosing the skeleton 

 or organ of support, thus giving more or less roundness to 

 the surface of the whole mass. But as it is for the most part 

 extremely delicate in structure, the cessation of life almost 

 renders it semifluid, whereby it runs off the skeleton in some 

 cases like oil. Being, too, of an albuminous nature, it col- 

 lapses like glue when dried upon the skeleton in its fresh state, 

 or coagulates upon it when placed in spirit. Both are pre- 

 servative means in which the altered sarcode, so long as it is 

 kept from putrefying (when it becomes exposed to the ravages 

 of fungi), will last as long as the horny parts of the skeleton ; 

 but of course, on drying, its structure is greatly obliterated, 

 although not so much so when coagulated and contracted by 

 the astringency of spirit. 



Tender and delicate, however, as the structure of the sarcode 

 and its soft contents are, especially in the calcareous sponges 

 (where there is no horny fibre, and therefore nothing to hold 

 the spicules together but the living sarcode), we may observe 

 the calcareous sponges growing upon the under surface of 

 rocks on the sea-shore to increase in size and develop their 

 forms there in the midst of daily washing by the falling 

 and rising of the tides, to say nothing of the accompanying- 

 waves which are often rendered more or less boisterous by 

 the wind ; while if life were to be abstracted for an instant 

 they would go to pieces immediately, just as " diffluence " 

 takes place in animalcules under similar circumstances, or as 

 a bunch of iron-filings kept together by a galvano-magnetic 

 current falls to pieces when the circle is broken. Such is the 

 power of life in keeping together the particles of which these 

 living structures (which crumble to pieces under the finger 

 and thumb when dry) are composed ! 



In using the term " sarcode " for the pulp-like part of 

 sponges generally, it must be understood to imply that it is 

 compounded of many parts, each of which requires a particular 

 description. 



Thus, when we come to examine the sarcodic mass micro- 



