372 
RHIPICEPHALUS SANGUINEUS: VARIATION IN 
SIZE AND STRUCTURE DUE TO NUTRITION. 
By NORMAN CUNLIFFE, B.A. 
Student in Medical Entomology. 
(From the Quick Laboratory, University of Cambridge.) 
(With 4 Text-figures.) 
Prof. Nuttall has suggested that I should continue his investi¬ 
gations (1913) on variation in size and structure due to nutrition, using 
other species of Rhipicephalus and species of other genera. 
The variation in size obtained with Rhipicephalus sanguineus, the 
species used in this experiment, was not as pronounced as that recorded 
in the experiment dealing with Rhipicephalus appendiculatus, owing 
probably to the great mortality in both fully gorged individuals and 
those which had been removed from the host whilst only partially 
gorged. The only larvae available had been kept three months, and 
the majority were in a weakened condition; as in other raising experi¬ 
ments the yields from larvae of a similar age have been poor. 
However, an examination of tbe material successfully raised clearly 
showed that the structural variation produced by malnutrition in 
Rhipicephalus appendiculatus is produced similarly in this species of 
Rhipicephalus, the results of the two experiments being practically 
identical. Hence it will only be necessary to give the experimental 
details and summaries of the measurements and points of structural 
difference between the normal and ill-nourished individuals of the 
nymphal and adult stages. In order to make this series of experiments 
as uniform as possible, it has been considered advisable to present the 
results on the plan of Professor Nuttall’s paper. 
