74 



OUTLINES OF NATURAL HISTORY. 



intestine is a curious organ, wliicn is generally known as 

 the "ink-sac" (fig. ^2, i). This is a little bag or mem- 

 branous sac, filled Avith 

 a jet-black semi-fluid 

 material — the "ink" 

 — which the animal 

 has the power of squirt- 

 ing out at will. The 

 tube which leads from 

 the ink-sac opens at 

 the base of the funnel, 

 and the "ink" can 

 thus be thrown into 

 the water outside. 

 The animal according- 

 ly, when threatened 

 by any danger, emits 

 a jet of this inky fluid, 

 and makes its escape 

 under cover of the 

 cloud which it has thus 

 raised. 



The remaining in- 

 ternal organs which 

 mainly concern us, are 

 the heart and gills. 



Fig. 32.-Diagram of the internal anatomy of a ^^^ ^,^f '^ receives the 

 Cuttle-flsh (altered from Huxley), m Jaws ; pure blood, whlch has 

 >i Nervous ring sun-ounding the gullet; p pflsspd thrmio-li fha. 

 Intestine, opening at the base of the flm- P^^sea tnrougn tUe 

 nel if); i Ink-sac, also opening at the base glUs, and distributes 

 of the funnel ;i/ Gills; .Skeleton. ^^ ^^ ^j^ ^^^^,^g ^^ ^j^^ 



body. The gills are the breathing-organs, and are two 

 in number. They are pyramidal in shape, and the im- 

 pure or venous blood is submitted in them to the action 

 of the oxygen contained in the water, which is freely 

 admitted to them; and which, after passing over their sur- 

 face, is again expelled from the funnel. 



Lastly, we find that the soft and yielding body of the 

 Calamary is strengthened and supported by a singular 



