Saxton.—Contributions to the Life-History of Callitris . 565 
in the individual development, the position of the archegonia is usually 
a correlated character, yet phylogenetically it may well have been otherwise. 
Nevertheless evidence from abnormalities is not always reliable, and may 
be easily used beyond its legitimate extent, so this suggestion is put forward 
with some hesitation. 
The position of the archegonia in Araucaria and Agathis , especially in 
the latter, is similar to that here described, and Seward and Ford ( 17 ) regard 
this as a primitive character, with which view the present writer is entirely 
in agreement. 
In this connexion something may be said in regard to the points 
of resemblance with Sequoia sempervirens , as worked out by Lawson (6). 
Other writers had previously mentioned some of the peculiarities in this 
remarkable Conifer, but the life-history was fully described for the first time 
by L awson, and it is therefore found most convenient to refer to his account 
only. 
Two points of resemblance stand out sharply, (i) The position of the 
archegonia, and (ii) the similarity in size and organization of male and 
female nuclei. 
A possible relationship between Sequoia and the Cupressineae has been 
suggested before by Arnoldi (1), and in many respects the Callitrineae may 
be considered to supply the missing link, agreeing with Cupressineae in 
their more obvious, with Sequoia in some of their more recondite, characters. 
This relationship, if admitted, would tend to the view that the Calli¬ 
trineae represent a relatively ancient type as compared with the Cupressineae, 
and other considerations support this view. There can be no doubt that 
Callitris is more nearly related to the Cupressineae than in Widdringtonia , 
and there are many indications that Callitris is the more specialized type of 
the two. Evidence of this would be largely a repetition of Table II below 
(which see). It seems quite clear to the writer that specialization in the 
Cupressineae must have proceeded on similar lines, although a wide gap, as 
shown above, separates the two tribes. The main change must have been 
increase in the number of cone-scales, accompanied by sterilization of some 
of them, the culmination of the process being reached in Cupressus. 
The second important conclusion is that, although fairly closely allied, 
the genera Widdringtonia and Callitris are quite distinct, and should 
undoubtedly be kept apart, as recently urged by the late Dr. Masters ( 9 ). It 
is unfortunate that, in the paper cited, a well-known species of Callitris 
should have been described by the author as a new species of Widdringtonia. 
The necessary correction was made by the author himself shortly after (10), 
but in the meantime it had been admitted in the first paper (loc. cit.) that 
the supposed new species to some extent broke down the distinction between 
the genera, and in consequence the conclusion lost much of its weight. 
The writer has already expressed ( 13 ) the opinion that the two 
