PEOOFS OF ORGANISING MIXD :]21 



same size as ourselves, enn only he seen by microscopes, and 

 that with improved instruments the various tools we use, as 

 well as our articles of furniture, our food, and our tahlc-fit tings 

 (knives and forks, dishes, glasses, etc., and even our watches, 

 our needles and pins, etc.) become perceptible, as well as the 

 food and drinks which are seen also to move about and dis- 

 appear; and when all this is observed to recur at certain def- 

 inite intervals every day, there woidd be great jubihition over 

 the discovery, and it would be loudly proclaimed that with 

 still better microscopes -all would be explained in terms of 

 matter and motion ! 



That seems to me very like the position of modern physiol- 

 ogy in regard to the processes of the growth and development 

 of living things. 



Insects and their Metamorphosis 



We now have to consider that vast assemblage of small 

 winged organisms constituting the class Insect a, or insects, 

 which may be briefly defined as ringed or jointed (annuluse) 

 animals, with complex mouth-organs, six legs, and one or two 

 pairs of wings. They are more numerous in species, and 

 perhaps also in individuals, than all other land-animals put 

 together; and in either their larval or adult condition supi)ly 

 so large and important a part of the food of birds, that the 

 existence of the latter, in the variety and abundance we now 

 behold, may be said to depend upon the former. 



The most highly developed and the most abundant of the 

 insect tribes are those which possess a perfect metamorphosis, 

 that is, which in their larval state are the most comi)letely 

 unlike their perfect condition. They comprise the great orders 

 Lepidoptera (butterflies and moths), Coleojitera (beetles), 

 Hymenoptera (bees, ants, etc.), and Diptc^-a (two-winged 

 flies), the first and last being those which are perha])s the most 

 important as bird-food. In all these orders the eggs produce 

 a minute aTub, maggot, or caterpillar, a- they are variously 

 called, the first havino- a distinct head but no legs, the second 



