ON THE GROWTH, ETC., OF SOME MARINE ALG#. 101 
Observations on the Growth and Time of /Appearance of some of 
the Marine Alge, &c. Ву J. Cocks, Esq., M.D., Honorary 
Member of the Dublin Natural History Society. Commu- 
nicated by Вовквт Hupson, Esq., F.R.S., F.L.S. 
[Read March 3rd, 1859.] 
Iw the course of conversation, when I was favoured last autumn 
with a call from Dr. Hooker accompanied by Dr. Harvey, of 
Trinity College, Dublin, I made some remarks on the growth and 
time of appearance of several species of the marine Algæ, to which 
these gentlemen thought I ought to give publicity. I have therefore 
much pleasure in availing myself of the present opportunity to 
contribute some additional facts to the rather limited knowledge 
we at present possess of a branch of natural history which, for 
some years past, has excited an unusual degree of interest, And, 
upon the threshold of this paper, I will observe that whoever adven- 
tures upon this branch of natural history with a view to follow 
it out to its remote conclusions, must necessarily become a practical 
collector. 
In the course of this occupation he will observe many interest- 
ing facts, connected with the varied objects to which his atten- 
tion will be especially directed, and the elucidation of which will 
require close and philosophical consideration. 
I trust I may, without presumption, lay claim to an opinion on 
the subject, derivable from an experience of fifteen years, during 
which period I have almost exclusively devoted my time and 
attention to its pursuit. I have not only carefully examined the 
vicinity of Plymouth, so rich in marine Algæ, but I have with 
equal attention extended my researches for several miles both to 
the eastward and westward of the same place. 
In the year 1855 I commenced the publication of the * Algarüm 
Fasciculi;' and since that period my explorations of the harbour 
and the coasts have been continuously and carefully repeated, over 
and over again, because it became imperatively necessary that J 
should provide myself with at least 700 specimens, including ten 
different species of Algæ, every consecutive two months, In order 
to accomplish this, it became necessary that I should traverse and 
examine a large extent of the shores in the neighbourhood. 
Whilst engaged in this laborious occupation, which nothing but 
zeal born of love for the pursuit could have enabled me to carry 
out at this advanced period of my life, my attention was forcibly 
drawn, not only to the growth, but also to the period of the 
LINN. PROC.—BOTANY. I 
