76 A. e. OUDEMANS, NOTES ON ACARI. 



Ill 1881 Bkrlese published his essay: II polimor- 

 fismo e le partenogenesi di alcuni Acari 

 (G a m a s i d i) (S u n t o) in Bull. So e. E n t o m. 1 1 a 1. 

 voi. 13, fase. 3 and 4. This extract is followed by the real essay 

 with the same title (Bull. S o c. En to m. I tal., 1882, vol. 

 14, fase. 1), fortunately to those who are less conversant with 

 the Italian language, translated in french : Polymor- 

 phisme et parthénogenèse de quelques Aca- 

 riens (G a m a s i d e s) in the Archives Italiens de 

 Biologie, V. 2, fase. 1, 1882. 



In this essay Bert.ese records bis results of a simple 

 examination of different G a m a s u s. He firmly 

 believes in their polymorphism and parthenogenesis. He has, 

 however, never bred them! 



»A présent, grâce aux recherches de Hermann, Koch, Kramer, 

 Méguin, etc., le nombre des Gamasides connus, touche à la 

 centaine, (lette grande quantité d'espèces, qui, si c'était exact, 

 nous permettrait de considérer le genre Gamasus comme le 

 groupe le plus riche en espèces de tout l'ordre des Acariens, 

 dérive sans aucun doute du polymor])bisme de ces animaux 

 de la même manière que l'immence quantité des individus de 

 chaque espèce, est une conséquence de leur pathénogénèse." 



Thus he adopts larvae, protonymphae, deuto- 

 n y m p h a e, males, females and — notwithstanding 

 Michael has shown by breeding two species, that the development 

 of Gamasids is binymphal — also t r i t o n y m p h a e. Further 

 according to different circumstances the three kinds of nymphae 

 may be soft or hard — the latter he calls nymphae coleo p- 

 tratae. Further the larval stage and one or two nymphae 

 stages may be suppressed - and so on. So he discerns of (ram«- 

 sns tan/n.^ two series, the normal and the anomalous one. 



The first, normal series is as follows : Larva, normal 

 nympha, adults. (Query: one, or two, or three nymphae?) 



The st'cond, anomalous series is as follows : proto- 



