156 REPORTS ON THE STATE OF SCIENCE.—1912. 
The actual time of pairing must vary considerably, as the size of the 
foetus at a given time varies. This can be seen in Table XI., showing 
the B. musculus foetuses measured by me. It seems probable that 
pairing takes place during the summer, and that the young are born in 
the winter or early spring months.’ The young when born are said to 
be from a quarter to a third the length of the mother. A whaler told me 
of a foetus of B. sibbaldu (Gray), 19 feet long which was seen by him. 
He considered that this was very near its time of birth. It is agreed 
that after birth the young grow quickly. There was a_ suckling 
_ estimated at 50 feet long with the female Blue whale (B. sibbaldti, 
Gray) labelled No. 2 in Table IIT. A suckling of this length is supposed 
to be not more than a year old, and it is said to remain with the mother 
for about a year. 
5. Probable varieties of the common ‘ Finner.’—The Norwegians 
believe that there are at least two varieties of the ordinary ‘ Finner’ 
(Balenoptera musculus, L.). Slightly differing accounts have been 
given as to the exact differences between the varieties, but the fact that 
there are variations as regards colour appears to be firmly established. 
Thus, Haldane® was informed that there were three varieties—large 
brown, dark grey, and smaller black. Lydekker !° gives the varieties as 
darker, lighter, and yellowish. There is also the ‘ Bastard whale’ of 
Cocks, which is supposed to be a cross between Balenoplera muscu- 
lus (L.), and Balenoptera sibbaldii (Gray). Southwell" says that this 
is larger than the type of the former species, and that it has grey on the 
under-surface. The anterior baleen-plates are white and the remaining 
portions darker than usual. Undue importance must not be given to 
colour differences alone. It is well known that after death the intensity 
of the colour alters if the body has been exposed for any length of time, 
and no doubt many colour descriptions have been taken from individuals 
which have been dead for some time. However, it appears certain that 
differences are found commonly among individuals of Balenoptera 
musculus (L.), B. sibbaldu}? (Gray), and Megaptera longimana** 
(Rud.). The variations may be due to age, or may be merely natural 
variations depending perhaps on the nature of the sea in which the 
animals live. The differences given by the Norwegians are generally 
colour differences alone, but Lydekker' states that the varieties may 
also be distinguished by their food. , 
I elicited the following information on this question of varieties. 
There are two distinct kinds of ordinary ‘ Finners’ (other than the 
Bastard whale apparently). A smaller variety is of the usual dark blue- 
grey colour on the upper parts of the body, and is fairly hard to capture, 
showing an amount of cunning comparable with that of the Sejhval 
(Balenoptera borealis, Lesson) and of the Humpback (Megaptera 
longimana, Rud.). 
8 Vide the cases of Humpbacks in Iceland and California, above. 
* Haldane, Ann. Scot. Nat. Hist., April 1908. 
10 Lydekker, Proc. Zool. Soc., 1911. 
“ T. Southwell, Ann. Mag. Nat. Hist., vol. xvi., October 1905. 
Haldane, op. cit. 
% Haldane, Ann, Scot. Nat. Hist., April 1905. 
Lydekker, op. cit. 
