(GQ ab-c-cnl ))) 
Estcourt in Natal ; and early in 1897, Mr. Marshall, writing 
from that locality, informed me that he had succeeded in 
rearing three specimens of Zeracolus auxo, a wet-season form, 
from eggs laid by 7’. topha, a dry-season butterfly. In each 
of these two Pierine cases the close relationship of the 
seasonal forms was so manifest, that all the circumstances 
of their occurrence led one to expect the species-identity 
to be proved before very long; but it was otherwise in the 
ease of Precis octavia-natalensis and P. sesamus, notwith- 
standing the significant facts—very close resemblance in 
both larvee and pupe, occasional pairing of the two forms, 
and the existence of various intermediate examples—which 
favoured a similar conclusion. Thus it was with no ordinary 
interest that I received from Prof. Poulton Mr. Marshall’s 
announcement, in a letter dated June, 1898, that in three 
cases he had bred P. seswmus from the eggs laid by P. 
octavia-natalensis, and that I saw the actual specimens of 
parent and offspring in two of the three cases, which had 
been sent to the Hope Department of the Oxford University 
Museum. An excellent account by Mr. Marshall of what 
he rightly describes as “the most remarkable instance of 
seasonal variation as yet known” was published in July 
last.* What makes the case so striking is not alone the very 
great difference of the upperside—deep salmon-red with 
black borders and spots in ociavia-natalensis, and violaceous- 
blue streaked with black, and a continuous series of 
salmon-red spots in sesamus—but that of the underside 
also—almost the same as the upperside, but pinker in octavia- 
natalensis, and very dark greenish-bronze with black 
streaks in sesamus. Owing to the latter disparity nothing 
could be more different than the appearance of the 
two forms when at rest, octavia-natalensis being very con- 
spicuous, while sesamus is well concealed ;7 and this wide 
* See ‘‘Seasonal Dimorphism in Butterflies of the Genus Precis, Doub.” 
(Ann. and Mag. Nat. Hist., (7), 11, p. 30 (1898).) 
+ The rarely-occurring intermediate examples, as I have pointed out 
(South-Afr. Butt., i, pp. 230, 231, and 233 ; 1887), exhibit a complete 
gradation as respects both upperside and underside. 
