1911] Gfirault, Species of Trichogrammatilce (Hymenoptera,). 163 



good or bad". The relation of a general insect parasite to its 

 hosts may be said to be homologous to those relations which a 

 general plant-feeding insect sustains to the plants upon which it 

 feeds; on the whole, both are mutually dependent and that is 

 equivalent to being mutually beneficial, not always to each oilier, 

 but to all organic nature. 



THE SO-CALLED RACES OF MINUTUM. 



Howard and Fiske (1911) have recently separated two bred 

 series of this species (the series morphologically indistinct) into 

 two race-species because of the fact that these two series have 

 different geographical origins coupled with the fact that each 

 series produces parthenogenetically a certain sex only. One of 

 these series was started from individuals obtained from a host 

 in Massachusetts while the other was started nearly at the same 

 time from individuals imported from Austria. The American 

 series produced only males (five generations) or were arrhenoto- 

 kous while the Austrian series of parthenogenetic females pro- 

 duced usually females or were usually the lyotokous (seventeen 

 generations or seventeen isolated females of which the progeny 

 was mixed once, female thirteen times and male three times). 

 Once or twice in the American series, the breeding was carried 

 to the second or third parthenogenetic generation ; that is, the 

 observed female was known to be a descendent in the second or 

 third generation from a first parthenogenetic female. In both 

 series normal sexual reproduction produced usually mixed sexes 

 but sometimes only females were produced. It seems unreason- 

 able to me to call these two series of individual species because 

 of the observed facts, for certainly what we know of the progeny 

 of parthenogenetic females throughout the entire animal king- 



7. Unless it is some phase of parasitism like double parasitism. 



