two forms certainly oceur in copuld.* But if this evidence 
were wanting there would still be strong presumptive evi- 
dence that the forms are associated by syngamy and synepigony. 
Thus, so far as our knowledge extends, dorippus occurs as the 
only form in certain parts of N.E. Africa alone. From this, 
its metropolis, dorippus spreads on all sides, its individuals 
existing intermingled with those of chrysippus, becoming less 
and less numerous until they finally die out. Thus if we 
trace the two forms eastward we find them both abundant 
at Aden; further east, at Karachi, dorippus is well known, 
but very scarce as compared with chrysippus; in Southern 
India it is a great rarity, if indeed it is known at all on the 
mainland ; in Ceylon a single specimen was captured by Col. 
Yerbury in 1891, and since then others have been taken.T 
Further east I have never heard of a specimen. Similarly 
when it is traced southward in Africa, dorippus is dominant 
in the coast strip of British East Africa, where it constitutes 
about three-quarters of the total number of individuals. 
Further to the south it becomes rarer and rarer, until in 
Natal and the Cape, if it occurs at all, it is even rarer than 
in Ceylon.t Such a distribution is consistent with the inter- 
pretation that dorippus and chrysippus are two forms in one 
syngamic community. It is difficult on any other hypothesis 
to account for the facts which we observe on the outskirts of 
* Speaking of his experience at Aden, Col. Yerbury says: ‘‘I have 
taken them [the forms of chrysippus] in coitu in every possible com- 
bination.” (Journ. Bomb., Nat. Hist. Soc., vii. (1892), p. 209.) 
+ See Major N. Manders, F.Z.S., in Journ. Bomb. Nat. Hist. Soe., xiv 
(1902), p. 716 :— 7 
*‘The first specimen of this insect [dorippus=klugii] in Ceylon was 
captured by Lieut.-Colonel Yerbury at Trincomalis, April 15th, 1891. . .” 
Of five or six more recent examples Major Manders writes, ‘“‘ These speci- 
mens were captured by Mr, Pole at Puttalam on the east coast and Ham- 
bantotte on the south coast in the dryest and perhaps most arid portion of 
the island. It is evidently widely distributed in the desert portion of the 
island and is possibly not uncommon.” 
‘The distribution of this insect in India cannot yet be fully known ; it 
is rare in Canara, but is not yet reported from the plains of the Deccan, 
or Southern India, so far as I am aware, though it probably exists.” The 
occurrence of dorippus at Bombay, Kutch, and Sind had been previously 
published by Major Manders and ‘the late Mr. de Nicéville in Journ. As. 
Soc. Bengal, vol. Ixviii, Pt. ii, No. 3, 1899, p. 170. 
+ Mr. Roland Trimen tells me that he knows of only three South- 
African dorippus :—two from Durban and one from Pretoria. The latter 
and one of the former were taken by Mr. W. L. Distant (Ann. Mag. Nat. 
Hist. (7), vol. i, 1898, pp. 48, 49). 
