uniosual for unfed females). Some of these eggs developed into 

 normal ticks but most were not delivered into the arms of gene's 

 organ and therefore did not hatch. In the sajne paper, Robinson 

 reviewed reports of partial twinning in other tick species. Leg 

 anomalies have been reviewed by Campana (194-7). 



Symbiotes 



Tissue cells of many normal insects and ticks harbor living 

 microorganisms that for the most part exert no harmful effects 

 on these cells. In fact, some of them may be distinctly benefi- 

 cial to the hosts, carrying out their part of a mutually helpful 

 relationship. _^Steinhaus (19^7)_7 



In some respects, the relationships between arachnids and 

 their symbiotes are very similar to those between insects and 

 theirs. Among noteworthy differences, however, appear to be the 

 absence of raycetomes in ticks, though some mites have these struc- 

 tures. Furthermore, most tick symbiotes occur in the meilpighian 

 tubules and in the ovaries instead of in the alimentary tract, 

 though this may not be true for certain of the rickettsiae. The 

 two families of ticks are similar with respect to symbiotes; in 

 both the sajne organs are associated with microorganisms. They 

 differ, however, in the manner of ovarial infection. /"Steinhaixs 

 (19^7) J 



Intracellular clusters of large masses of typical rickettsiae 

 were discovered in salivary gland acini of 0. moubata by Hertig 

 and Wolbach (l92Zt). Intracellular symbiote's were not found in 

 larvae (? nymphs) of 0, moubata by Cowdry (192 5C,1926A, 1927), 

 though they were denSnstrated in Argas persicus and in Otobius 

 megnini . Other extensive reviews of symbiotes in ticks are 

 those of Mvidrow (1932) and Jaschke (1933). 



In 0. lapubata , unlike ixodid ticks, symbiotes, probably of 

 a bacterTal nature, do not occur in the anterior ends of the 

 malpighian tubes but rather in about one-fifth of the length 

 of the tubes just posterior of the anterior ends. In this, 0. 

 moubata differs from A. persicus , in which Jaschke observed Tntra- 

 cellular symbiotes in masses as large as five microns in diaaeter 

 and containing as many as forty individual organisms each. 



_ 177 - 



