ger lost weight rapidly and in
two weeks moulted into the olive-green winter plumage. After a year, and
at the beginning of the normal breeding season, "individual tanagers
and bobolinks were gradually brought under normal conditions and
activities," and in every case moulted from nuptial plumage to nuptial
plumage. "The dull colours of the winter season had been skipped." The
author justly claims to have established "that the sequence of plumage
in these birds is not in any way predestined through inheritance...,
but that it may be interrupted by certain factors in the environmental
complex."

XVI. GEOGRAPHICAL DISTRIBUTION OF PLANTS. By Sir William Thiselton-Dyer,
K.C.M.G., C.I.E. Sc.D., F.R.S.

The publication of "The Origin of Species" placed the study of Botanical
Geography on an entirely new basis. It is only necessary to study the
monumental "Geographie Botanique raisonnee" of Alphonse De Candolle,
published four years earlier (1855), to realise how profound and
far-reaching was the change. After a masterly and exhaustive discussion
of all available data De Candolle in his final conclusions could only
arrive at a deadlock. It is sufficient to quote a few sentences:--

"L'opinion de Lamarck est aujourd'hui abandonee par tous les
naturalistes qui ont etudie sagement les modifications possibles des
etres organises...

"Et si l'on s'ecarte des exagerations de Lamarck, si l'on suppose un
premier type de chaque genre, de chaque famille tout au moins, on se
trouve encore a l'egard de l'origine de ces types en presence de la
grande question de la creation.

"Le seul parti a prendre est donc d'envisager les etres organises comme
existant depuis certaines epoques, avec leurs qualites particulieres."
(Vol. II. page 1107.)

Reviewing the position fourteen years afterwards, Bentham
remarked:--"These views, generally received by the great majority of
naturalists at the time De Candolle wrote, and still maintained by a
few, must, if adhered to, check all further enquiry into any connection
of facts with causes," and he added, "there is little doubt but that if
De Candolle were to revise his work, he would follow the example of
so many other eminent naturalists, and... insist that the present
geographical distribution of plants was in most instances a derivative
one, altered from a very different former distribution." ("Pres. Addr."
(1869) "Proc. Linn. Soc." 1868-69, page lxviii.)

Writing to Asa Gray in 1856, Dar