SEA WEEDS. 
209 
be artificial, but observation has proved that “ it nearly coincides 
with the natural classification of them according to their struc- 
ture and development.” The rest of the introductory chapter 
treats of salinity of water and change of temperature as affecting 
seaweeds, their distribution in time and space, their growth and 
their economic use. Mr. Murray also gives instructions as to 
the best method of collecting, both from the shore and by dredge, 
and how to mount and preserve specimens dry and in spirit. 
Most books on seaweeds deal first with the group of RJiodo- 
phycece or red algae, as being that which contains the most 
complicated and highly differentiated forms, descending through 
the brown and the green to the blue-green or simplest form of 
seaweed. Mr. Murray, however, deals first with the familiar 
brown seaweeds — the first to meet the eye of any collector. The 
Fucus or bladder-wrack, which we have all popped with such 
POSTELSIA PALM/EFORMis (enlarged). 
satisfaction in childhood, the long tangles floating on the surface 
of the waves, and many of their representatives in foreign oceans, 
are here figured. To those who have not access to any large 
herbarium many of these figures will be of much interest, as 
showing them forms which are closely related to our British 
ones, though found only in the southern hemisphere. Macrocystis, 
the largest of all seaweeds, with its fronds hundreds of feet long, 
supported on the surface of the water by means of air-floats, and 
Postelsia, rightly named palmceformis from its palm-like appear- 
ance, are among the foreign forms figured here. It is an added 
attraction to this book that many of the illustrations are new, 
and the rest have not, as a rule, ever appeared in any text-book 
before. 
