CURIOUS WAYS OF GETTING FOOD. 771 



" So, naturalists observe, a flea 

 Has smaller fleas that on Lira prey ; 

 And these have smaller still to bite 'em, 

 And so proceed, ad infinitum.'''' 



The variety of animal food is, therefore, as broad as animated 

 nature. Hence, we find great variety of means and methods for pro- 

 curing subsistence. Particularity in food implies especial or efficient 

 means of getting that food. The strange appendages of animals, their 

 form, color, and habits, have to do more with the prehension of food 

 than with any other function. It will be interesting to briefly survey 

 the animal kingdom Avitli reference to this marvelous adaptation. Its 

 origin we will not discuss. 



The simplest manner of procuring food is shown by the tapeworm 

 and some other intestinal animals. These feed on the nutritive fluid 

 prepared in the alimentary canal of the animals which they inhabit ; 

 and, being destitute of mouth and stomach, absorb the already digested 

 food directly through the skin or body-walls. Probably this absorp- 

 tion does not require will or effort on the part of the parasite, but 

 takes place simply by the physical action known as osmose. It is thus 

 equivalent to the last step in the digestive process of higher animals. 

 Some parasites, as the larva of the tapeworm, which live in the muscles 

 and tissues, imbibe the animal juices by the walls of the body ; but 

 here the process as a whole is slightly higher, for this food probably 

 requires more elaboration or digestion. 



Fig. 1.— HAWK-MoTn {Sphinx quinguemaculatus). 



Any special modification or organ for procuring food is a great 

 advance beyond the method already described. Liquid food is more 

 easily prehended than solid, yet the means are various and remarkable. 

 Even the simplest organs are wonderful in their structure and action. 



Those butterflies and moths which take any food at all have a 



