Introduction to Animal Morphology. 7 



observed that the following inorganic materials are 

 found in animal bodies : Oxygen in all the fluids, 

 Hydrogen in the intestinal gases of vertebrates 

 with H2S, Carbonic acid in all tissues, Calcium 

 Fluoride in bones and corals, Magnesium Fluoride in 

 some corals, Water in all tissues from enamel which 

 contains 0*2 per cent, to the connective tissues of jelly 

 fishes with 99-5 per cent., Sodium Chloride also in all 



Peptone is a dialysable form of albumen formed in the process of 

 digestion, not precipitable by heat, dilute acids, nor alkalies. 



Fibrin is insoluble in water or NaCl, swells in dilute acids, and this 

 softened form is coagulated on boiling ; found in blood. 



Casein is probably a mixture of Alb. with a non-albuminous substance, 

 which is separated from it in digestion as a dyspeptone ; soluble in alkalies, 

 coagulable by mineral acids, precipitable by lime and magnesia salts, in- 

 soluble in water or NaCl. 



Keratin, the material of the cell-wall in epithelium, resembles casein 

 in many of its properties ; it may be a compound of several albumen- 

 derivates. 



Gerhardt regards these as similar in composition, but differing in 

 molecular arrangement. Lebonte and others regard them as each com- 

 posed of several radicles united in different proportions. From these are 

 derivable the following nitrogenous non-albuminoids : 



Protagon, present in nerve tissue. A mixture of Cerebrin Cn 



/ OiCieHaiO 



with Lecithin, a body derived from ) OiCisHaaO 

 Glycerin C.,11'"* OiPO /OH 



\ OC,H 4 



Leudn C G Hn (NH 2 ) O 2 present in the tissues of Arthropods, in 

 pancreatic juice, &c. Ty rosin C^HnNOa found with Leucin and in 

 Cochineal. 



Kreatin CiHaNaOjH^O in smooth muscle, and with Kreatinin (C<H 7 N 3 O) 

 in blood and muscle. Guanin CsHaNsO in Ccstodcs and Siphonophora, 

 fishes and birds. Sarkin in the muscles of hares and ruminants. Xanthin 



and Urea CO { ^jj 2 and Uroxanthin in urine. Chlorophyll 



in Turbcllaria and some green annelids. Mucin in mucus, 

 connective .;nd Jlclicin are two varieties of it in 



'/, in the intricellulur Milistuncc uflii 

 com. N is converted into Gelatin by boiling water or boiling 



