312 Genus Ixodes 



photograph, a number of females which have oviposited in a dish. He 

 states that oviposition lasts one month. 



Samson (1909, p. 221) states that oviposition commences about 14 

 days after the % has abandoned the host. 



Note : As stated by Nuttall (1908), the process of oviposition in the 

 other genera of Ixodoidea is essentially similar to that in Ixodes, having 

 been observed by him in Argas, Ornithodorus, Ixodes, Amblyomma, 

 Boophilus and especially in Haemaphy sails, the process being illustrated 

 by a series of sketches in the case of Haemaphysalis punctata. Lewis 

 (1892) has illustrated the process in Amblyomma, likewise by a series 

 of sketches. Samson (1909, p. 223) notes the fact that the process is 

 similar in Rhipicephalus, but this author's description is very imperfect. 

 As all the other Ixodidae possess a similar anatomical structure to the 

 foregoing, it is safe to conclude that they also oviposit ir a similar 

 manner. 



Relation to Disease. 



Redwater in Cattle : Ixodes ricinus is the only species of Ixodes of 

 which we have a conclusive demonstration that it plays a part in the 

 spread of disease. This tick appears to be the chief carrier of redwater 

 (piroplasmosis) in cattle in northern Europe. Its association with red- 

 water was first observed in Finland by Kossel and Weber, in 1910, and 

 subsequently Kossel, Schiitz, Weber and Miessner (1903) demonstrated 

 experimentally that bovine piroplasmosis could be conveyed through 

 ricinus. These authors (pp. 50 et seq.) removed engorged and fecundated 

 ricinus from German cattle suffering from the disease, and collecting 

 the larvae that had hatched out from the eggs laid by the infected 

 females, placed them upon susceptible cattle. Kossel and his colleagues 

 carried out six experiments with larval ricinus, and they record that 

 the cattle developed redwater 8-14 days after they had been infested 

 with the larval ticks. In one of these experiments, carried out in 

 June, 1902, the infective larvae were derived from eggs laid by females 

 collected from cattle in the previous year (May-June, 1901). The ticks 

 had been exposed to all the rigours of a German winter. Kossel and 

 his colleagues also record an experiment in which a cow was successfully 

 infected through the agency of ricinus nymphs which had fed on infected 

 cattle in the larval stage. 



It is probable that ricinus is the carrier of redwater in Norway, and 

 it has been found associated with the disease in Great Britain and 



