Uigglesworth (l9'i-3 ) confirmed that in 0. moubata, blood 

 (haemoglobin) is absorbed by swollen epitheTial cells of the wall 

 of the large stoinach and its diverticula. In these cells, which 

 detach and remain free in the lumen, blood pigment is converted 

 into black globules that are ultimately discharged into the gut 

 cavity. Similar dark granules are dispersed through smaller 

 cells of the gut wall, but no black pigment can be seen in other 

 tissues or in the body cavity. The haemoglobin is digested more 

 or less to protohaematin and is demonstrable in the tick's haemo- 

 lymph probably as alkaline haematin. The gut contents are reddish 

 brown with black haematin deposits. No free iron can be detected 

 in the gut lumen or cells, or in other tissues, and no nephrocytes 

 containing haemoglobin derivatives casi be found. 



The type of host from which 0. moubata draws a blood meal may 

 be identified by the precipitin test more than six months follow- 

 ing feeding (laboratory studies at 20°C . and eighty percent rela- 

 tive humidity) (Weitz and Buxton 1953), or even for twelve months 

 (fowl blood meal, kept at 3CPC., ticks also fed on mouse) (Gozony, 

 Hindle, and Ross 19U.). 



Rectal Excretion 



As stated above, 0. moubata has no passage between the small 

 intestine and the rectal ampulla, and defecation does not occur. 

 Excretion of water ("'ijrination'" ) from the malpighian tubules 

 takes place only after the first nymphal stage has been reached 

 and a blood meal has been absorbed; this excretion is viscous 

 and dries within a few hours. In the weeks following the first 

 excretion only a slight amount of water is irregularly excreted 

 (but can be produced through various stimuli). This pattern is 

 similar in each developmental stage after the larva. 



Variations in tick excretion and a comparison of this function 

 according to species, morphology, number of hosts, size, duration 

 of development, quantity of blood ingested, and transmission of 

 disease orgamsms to vertebrate hosts have been analyzed by Enigk 

 and Grittner (1952). 



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