FIG. 196. PLANT-LICE. 

 a, wingless insect ; b, wingless insect. 



EVIDENCE FROM COLONIAL OR COMPOUND ANIMALS. 289 



race the latter forming social colonies which in their essential 

 nature may be deemed analogous to the zoophyte-stocks of lower 

 life. The single and undivided personality of a bee or an aphis 

 would at first sight seem to 

 admit of no question. Each 

 presents itself to view as an 

 active being, possessing no 

 structural connections with 

 neighbour - organisms, and 

 evincing all the apparent 

 marks and characters of an 

 ordinary "individual." But 

 our philosophy relies, as 

 already remarked, more on 

 the determination of what 

 an organism has arisen from, 

 than upon what its apparent 

 constitution may be. Hence 

 the consideration of a bee's origin contains the answer to the question 

 of its true nature. In the reproduction of the bee race, certain of the 

 eggs are impregnated or fertilised, whilst others are allowed to develop 

 without the performance of this process rightly deemed of essential 

 nature to the propagation of both animals and plants. Now, those 

 eggs of a queen-bee which she lays in an unfertilised condition, 

 invariably develope into drones, or male bees, whilst the fertilised 

 eggs become females, or queens, or neuters the latter being merely 

 imperfect females, on whom devolves the whole work of the hive. 

 In the plant-lice, the eggs normally produced by both sexes in the 

 autumn lie dormant all the winter, and then give rise to wingless 

 female aphides alone. These latter produce, in viviparous fashion, a 

 winged or wingless progeny, which in turn repeat the fertility of their 

 parents. As Huxley remarks : " The number of successive viviparous 

 broods thus produced has no certain limit, but, so far as our present 

 knowledge goes, is controlled only by temperature and the supply 

 of food. Aphides kept in a warm room, and well supplied with 

 nourishment, have continued to propagate viviparously for four 

 years." 



Now, close research has disclosed other cases of this apparent 

 violation of the ordinary rules of reproduction in the animal world. 

 We know that in certain saw-flies, some of the female insects will, of 

 themselves, lay unfertilised eggs, which develop into male saw-flies. 

 In some insects (Chermes; Coccus] no males have been discovered. 

 There are also certain caterpillar-like females among the butterflies 

 and moths (e.g. Psyche and Solenobia) which lay unfertilised eggs giving 

 origin to female insects like themselves, whilst from fertilised eggs 



