164 Miscellaneous. 



He supports this theory as follows : — In the first place he starts 

 from the truth, ascertained by the experience of breeders, that a 

 certain degree of diff'eronce between the parent individualities is 

 most favourable to the result of a crossing. Such differences which 

 are caused in the organism by the external conditions of life would 

 evidently be of no service in asexual reproduction. A disease which 

 made its appearance in an individual which propagated solely by 

 the method of gemmation would be inherited from generation to 

 generation and endanger the existence of the entire species. But 

 if a mingling of the diseased with perfectly healthy protoplasm 

 (such as must necessarily occur in sexual reproduction) be brought 

 about, "we have not merely the possibility, but even the highest 

 probability, of a rectification such as can be obtained in no other 

 way. It is, in Hatschek's opinion, in furnishing the opportunity 

 for such rectification that we must find the chief use of the existence 

 of sexually differentiated individuals among animals and plants. — 

 Prager mecliz. Woclienschrift, No. 46, 1887; Bioloqisches Gentral- 

 hlatt, No. 21, January 1, 1888, pp. 6'j4-66G. 



Notice of two neiv BrancMopod Crustacea from the Trans-Casjnan 

 Region. By Dr. Alfred Walter. 



The species described are as follows : — 



1. A^ms Ha'ckelii, n. sp. 

 A. lamina caudali coniformi, acuminata, incarinata neque spinulosa, 

 duplo longiore quam lata. Sinu postico scuti angulato armatoque 

 dentibus 30. Ramo longissimo primi pedis angulos scuti exce- 

 dente. Segmentis posterioribus 16-17 scuto non obtectis, post- 

 remis 6 apodibus. Colore scuti et corporis in vivo albido flaves- 

 cente, pedum rosacco. 



Hab. In a desert spring near Karadschabatyr, north of the Lower 

 Atrek, in the Russian Trans-Caspian. 



A female was taken early in May, together vrith species of 

 Estheria^ BrcmcJiipus, and some Cladocera and Ostracoda. The 

 species belongs to Grube's second group of Apus, in which there is 

 a caudal lamina separating the long caudal appendages (with A. pro- 

 ducfns, A. glacialis, &c.). It differs from all known allied species 

 in the unkeeled and spineless caudal lamina. 



2. Artemia asiatica, n. sp. 

 A. processibus caudalibus digitiformibus, setas 8-10 gerentibus, 

 antennis primis gracilibus filiformibus, apice setis 3 armatis. An- 

 tennis secundis crassis, corniformibus, apice acuminatis, duobus 

 tuberibus non dense setosis ad radicem eminentibus. 

 Hah. In a salt-spring between Bend-i-nadyr and the well of 

 Agaraet, in the mountain-desert east of Murgab, near the Afghan 

 boundary. 



Female, taken in April 1887. Colour of the living animal tile- 

 red. — Bull. Soc. Imp. Nat. de Moscou, nouv. ser., tome i. (1887), 

 pp. 924-927. 



