Eighth Report of the State EbTOMOLOQlBT* 267 



tinue thus counting for ten hours a day, it would require twenty- 

 eight days to count a million, and consequently, eleven months 

 of such labor (an obvious impossibility, for utterly beyond human 

 power of endurance) to have counted the aphides upon rhat 

 little cherry tree. 



Eapidiiy of Propagation. 

 The rapidity of propagation shown in some insects, is also 

 without a parallel elsewhere. Perhaps, in the aphides or plant- 

 lice, it attains its maximum, where successive generations of 

 living young, all of which are females, continue to be produced 

 throughout the summer months, without the presence of the male, 

 by a process which has been compared to, and, indeed, styled, 

 budding. Professor Riley, in his recent studies of the hop- vine 

 aphis, Phorodon humuli, has observed thirteen generations of the 

 species in the year. Now, if we assume as the average number of 

 young produced by each female to be 100, and that every individual 

 shall attain maturity and produce its full complement of young 

 (which, however, never can occur in nature), we would have, 

 as the number of the twelfth brood alone (not counting those 

 of all of the preceding broods), 10,000,000,000,000,000,000,000 

 (ten sextillions) of individuals. Where, as in this instance, 

 figures fail to convey any adequate proper conception, may I ask 

 you to take space and velocity of light as your measures? Were 

 this brood, as above given, marshalled in line with ten individu- 

 als to a linear inch, touching one another, the procession would 

 extend to the sun (a space which light traverses in eight minutes), 

 and beyond it to the nearest fixed star .traversed by light only m 

 six years), and still onward in space beyond the most distant star 

 that the strongest telescope may bring to our view, to a point so 

 inconceivably remote that light could only reach us from it in 

 twenty-five hundred years. How fortunate it is for the human 

 race, that in view of such amazing capabilities of increase in the 

 insect world, so many counter-checks have been provided by 

 Providence for the prevention of unrestricted development in a 

 single direction, that all nature may still work together in liar- 

 mony, when viewed in its broadest aspect. 



