INTRODUCTION. 
Algology is the science that treats of the structure, habits, and classification of 
Algae. Alga singular, and Algae plural, meaning sea-weed, or sea-weeds, is the 
name applied to a large class of aquatic Cryptogamia, or flowerless plants. Algae 
are formed of endochrome, gelatine, and membrane ; the endochrome occupies the 
cavities of cells formed by the gelatinous and membraneous matter. They have no 
woody fibre, and no continuous vessels like the phaenogamous plants. They inhabit 
all countries where water is found. All parts of the ocean, all rivers, lakes, pools, 
the spray from the billows, and drip from the fountain, form suitable habitations for 
Algae. Many species are widely spread over the globe, while others have a very li¬ 
mited range. Many of the European species are identical with those found in Ame¬ 
rica, while some species found in particular localities would be sought in vain else¬ 
where. Algae existed in very remote times. The fossil remains bear witness to their 
antiquity and profusion. They are found on high mountains, and in quarries at great 
depths from the surface. I have several specimens and distinct species of fossil Algae 
in carbonate of lime, a lithographic stone, quarried at Solenhofen, Germany, 350 feet 
below the surface. The marine origin is evident, from shrimp, crabs, and fishes of 
various species found in the same quarry, also a horse-shoe of the identical species 
that now inhabit our waters, and which annually in June deposit their eggs near high 
water mark, secure from the eels in the sand. Lamouroux, a French Algologist, has 
written largely on the geographical distribution of Algae ; his writings in the An- 
nales des Sciences Naturelle, maybe read with much profit by the curious in that de¬ 
partment. 
In the Linnaean system, Tremella, Fucus, Ulva, and Conferva, comprise the four 
grand divisions in aquatic plants. Since the time of Linnaeus, important modifications 
and changes have been made in the classification of Algae. Agardh of Sweden, who 
devoted much time and learning to the subject, separated the aquatic cryptogamia 
from the general system, and under the name of Algology, has aided largely to increase 
our knowledge, and adorn the science. Hudson, Greville, Harvey, and other writers 
on British Algae, have introduced many new species ; and by their accurate descrip¬ 
tions in organic structure, have enabled us to recognize many similar species in our 
own waters. 
Much remains to be done in this country towards advancing the science of Algo¬ 
logy. A few lovers of the natural sciences have devoted their leisure hours in col¬ 
lecting the Algae convenient to them ; and some by friendly exchanges have very 
large and interesting collections. One retarding cause is, probably, the difficulty ex¬ 
perienced in ascertaining the exact position of each plant in the natural order, and 
in acquiring the specific name of each plant. The organic structure and organs of 
