BIHANG TILL K. SV. VET.-AKAD. HANDL. BAND 28. AFD. IV. N:0 8. 47 



the insectivorons lizards as a rule inhabit dry ground where 

 moisture is scarce and their food does not contain so much 

 fluid either. It is therefore of importance that this flnid and 

 its digestible contents may be reabsorbed. The reabsorption 

 takes more easily place if the area capable of reabsorption is 

 large. A dilatation of the colon is consequently very useful 

 for the animal and when the dilatation for reasons mentio- 

 ned above, is excentric it leads to the development of a coc- 

 cnm. The recurved shape of the coecum as it often appears 

 is a differentiation which is favourable because in such a 

 coecum the fluid is easily admitted especially if the colon 

 contracts itself, but the large chitinous pieces do not so easily 

 find their way in there. Is must also be observed that the 

 digestible contents of legs and joints of insects cannot be so 

 rapidly reabsorbed during the passage through the small in- 

 testine. It is therefore of importance that such pieces can 

 be retained in the coecocolic tract so that they may be so to 

 say sucked out there. — In the iutestinal canal of herbivo- 

 rous lizards as well as other animals the vegetable food 

 may be used or digested according to two different plans 

 or systems. Some animals eat and digest the vegetable food 

 so to say after the plan of carnivorous animals, and their 

 digesting apparatus not being especially adapted to such 

 food they are restricted to the digestion of the contents of 

 the plantcells, protoplasm, amylum etc. The true herbivo- 

 rous animals again have special adaptations for the decom- 

 position and utilization of cellnlose. It might be said me- 

 taphorically that the animals of the former category although 

 feeding on vegetable matter were carnivorous because they 

 cannot digest other substances than such as can also be di- 

 gested by a true carnivorous animal. As a rule such ani- 

 mals are not really and truly herbivorous, but rather omni- 

 vorous^ although the vegetable food may in some instances 

 become quite predominant as in some turtles and also in some li- 



' Carnivorous animals which, when their normal food is lacking, turn to 

 a herbivorous diet can of course not digest the vegetable matter but in the 

 manner suggested above. A very striking and instructive example of such 

 a thing is oifered by Mr. Gf. Kolthoff's observations on some ice-bears on 

 King Charles land in the summer 1899. When the ice was all gone and the 

 seals had disappeared with the same the poor bears were robbed of their 

 normal means of subsistence and had to turn their attention to herbs and 

 straws. Mr. Kolthopp coUected excrements of such bears consisting of the 

 fibrous skeletons so to say of straws and plants which had completely un- 

 digested passed through the intestinc of the bears. 



