35 



concourse, beyond that which ray observations on the 

 Aphides in 1841 and 1842 had furnished me with*. But, 

 although I laid down the volume with most grateful 

 feelings towards the ingenious author for his useful collec- 

 tion of scattered memoirs detailing the phenomena, for 

 his confirmation by personal researches of some of them, 

 and his generalization of the whole, I sought in vain for 

 any observation which really explained them, or anything 

 purporting to be explanatory of them, save the phraseology 

 and figurative expressions above cited : no organic condi- 

 tion is pointed out as being related or essential to the ( Lu- 

 cina sine concubitu.' 



With regard also to figurative language in science, unless 

 the metaphor be exact, it misleads rather than explains. 



Thus, as to the term Amme. The development of the 

 secondary germ-cell in the body of a larva is at the ex- 

 pense of the surrounding cells and fluids of that larva, 

 which therefore contributes food to the embryo ; but this 

 is rather as the mother of the viviparous vertebrate animal 

 contributes nutriment to its embryo, than as the wet-nurse 

 does to her foster-child : the relation of the offspring of the 

 parturient larva to its procreator is also very different from 

 that of the infant to the nurse that suckles and dandles 

 it ; and more closely resembles that of the foetus in utero. 



To rightly and clearly understand the phenomena we 

 must adhere closely to them and to nature, and be careful 

 not to be led astray by ambiguous or remotely figurative 

 expressions. 



No naturalist or physiologist has hesitated to call the 

 polype which propagates by gemmation a ' parent } in re- 

 lation to the young polype so propagated : it is true that 

 the parent has produced without preliminary sexual inter- 

 course in her own person, and she may have received ab ovo, 

 and not herself have developed the germ-cell w^hich was the 

 essential basis of the bud ; yet the term ' parent 5 is never- 



* 'Lectures on the Invertebrate Animals/ pp. 233-235. 



c 2 



