83 



0. Infescens {fldchcri). 0. prodotes and 0. diantaeus were known 

 chieHy as American, l)ut have recently been recorded in Europe under 

 other names by Martini, the synonymy being gix'en in an appendix, 

 in which a variety subochrca of Theobaldia anmdata is mentioned, and 

 the new name salinellus, Kdw., is given to the species recorded as 

 Aedes terriei, Theo., by Martini. 0. caspius, Pall., is recorded as a 

 great pest in the immediate neighbourhood of Copenhagen, and (). 

 curriei, Coq., is regarded as merely a variety of it. 



A final chapter deals with the biology of the three Danish species 

 of Anopheles, particularly .4. maciilipiiuiis. The habits of this species 

 and their bearing on the disappearance of malaria from Denmark arc 

 vej-y fully discussed. The author concludes that the usual explana- 

 tions" of the disappearance of malaria (improvements in drainage, 

 diminution of Anophelines, cpiininisation, etc.), are inadequate, and 

 argues that there has been a marked change in the blood-sucking habits 

 of A. maculipennis within the last century ; from being mainly 

 dependent on human blood, it has become almost exclusively an 

 attacker of domestic animals, especially pigs, over most of Europe 

 north of the Alps. The author attributes this supposed modification 

 in habits in Denmark to the changes in agricultural methods that took 

 place early in the last century, cattle being kept in increasing numbers 

 and housed in large stables during the greater part of the year. He 

 also remarks that this change in habits appears to have been accom- 

 panied by an increase in size of the insects, so that at the present 

 day the non-malaria-carrying North European race may be distin- 

 guished from the still malaria-carrying South European race by its 

 larger average size. After writing this chapter, the author found his 

 conclusions largely confirmed by Roubaud [R.A.E., B, viii, 141). 



Theiler (Sir A.). Diseases, Ticks, and their Eradication. — J I. Dept. 

 Agric, Pyetoria, ii, no. 2, Eebruary 1921, pp. 141-159. 



The tick-borne diseases occurring in South Africa are briefly reviewed, 

 and their causal agents and transmitters enumerated. These include 

 biliary fever in horses, caused by Nuttallia equi, carried by Rhipi- 

 cephalus evertsi (red tick) ; redwater in cattle, caused by Piroplasma 

 bigeminum, carried by Boophilus decoloratus (blue tick) ; gall-sickness 

 in cattle, caused by Anaplasma marginale, which has been experi- 

 mentally transmitted by B. decoloratus, but is also carried by Rhipice- 

 phalus spp. ; fevers caused by Gondcria {Piroplasma) mutans, carried 

 by red and brown ticks {Rhipicephalus spp.) ; fevers caused by 

 Spirochaeta theileri, carried by B. decoloratus ; African Coast fever, 

 caused by Theileria parva, transmitted by Rhipicephalus spp., including 

 R. simus (black-pitted tick) ; heartwater in cattle, sheep and goats, 

 caused by an ultramicroscopic organism, transmitted by the bont tick, 

 Amblyomma hebraeum ; biliary fever in dogs, caused by Piroplasma 

 canis, transmitted by the dog tick ( Haemaphysalis leachi) and by the 

 brown tick ( R. sanguineus) ; and a form of paralysis of sheep and lambs 

 said to be connected with the presence of the tick, Ixodes pilosus. 

 These diseases are divided into two groups, namely, those in which the 

 animal retains the infection in the blood after recovery and acts as a 

 reservoir of the virus, and those in which the blood of an animal that 

 has recovered becomes sterile and harmless. 



The life-histories of these ticks are given, and a list is included of 

 important points that require elucidation. The hosts of each are 



