ON THE GROWTH, ETC., OE SOME MARTXE ALGiE. 101 



Observations on the Growth and Time of Appearance of some of 

 the Marine Algae, &c. By J. Cocks, Esq., M.D., Honorary- 

 Member of the Dublin jS'atural History Society. Commu- 

 nicated by Egbert Hudson, Esq., E.E.S., E.L.S. 



[Read March 3rd, 1859.] 



In 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 Algae, 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 Algae, 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 ' Algarum 

 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 I 

 should provide myself with at least 700 specimens, including ten 

 diiferent species of Algae, 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 



