ECOLOGICAL BACKGROUND AND GROWTH BEFORE 1900 



35 



with the biotic control of some important 

 phases of ecological succession. 



The subdivision of the Httoial region of 

 the ocean into faunal provinces, as Dana 

 (1852, 1853), Packard (1863), and VerriU 

 (1866) have done for Atlantic coastal 

 waters, is based primarily on the observed 

 distribution of species and groups of species 

 and secondarily on physical factors such as 

 temperature and geographic features such 

 as capes. From the most southern Floridian, 

 through the Carohnian, Virginian, and 

 Acadian, to the most northern Syrtensian 

 province, the geographic faunas of these 

 naturalists suggest the biomes (biotic for- 

 mations) of more recent workers (cf. Shel- 

 ford et al., 1935). If proposed today, they 

 might be designated by biological terms to 

 suggest their taxonomic composition, rather 

 than by geographic names that suggest 

 their distribution. 



We now know that this is the historical 

 background against which to view the re- 

 markable work of VerriU and Smith (1874) 

 which, despite the praise given by Adams 

 (1913), did not receive the recognition or 

 have the influence among ecologists that 

 it merited. They found "three quite distinct 

 assemblages of animal hfe, which are de- 

 pendent upon and Umited by definite physi- 

 cal conditions of the waters which they 

 inhabit." These three primary groupings 

 were: (1) the animals of the bays and 

 sounds; (2) those of the estuaries and other 

 brackish waters; and (3) those of the cold 

 waters of the ocean shores and outer chan- 

 nels. 



In each of these assemblages, VerriU and 

 Smith recognized that certain kinds of ani- 

 mals are restricted to particular localities 

 because of their relation to the character of 

 the bottom or of the shore. "Thus," they 

 say, "there will be species, or even large 

 groups of species, which inhabit only rocky 

 shores; . . . others that prefer the clean 

 gravelly bottoms where the water is several 

 fathoms deep." These may be still further 

 divided. The mud, for example, has differ- 

 ent characteristics in different places, and 

 "the different kinds are often inhabited by 

 different groups of animals." In describing 

 the animals that Uve in these habitats, they 

 report: "It has not been found desirable to 

 mention, in this part of the report [the gen- 

 eral discussion], all the species found in 

 each, but only those that appear to be most 

 abundant and important." They also knew 



that the population during the day differed 

 from that found at night in the same spot 

 and that there were seasonal changes as 

 weU. 



This somewhat extended report of VerriU 

 and Smith's work indicates correctly that 

 they were impressed with the organization 

 of communities upon the basis of their rela- 

 tion with their physical habitat rather than 

 as a result of interrelations between constit- 

 uent organisms. The latter were not im- 

 known to them, for, among other instances, 

 they state that "SheUs of oysters provide 

 suitable attachment for various shells, bry- 

 ozoans, ascidians, hydroids, sponges, etc., 

 which could not otherwise maintain their 

 existence on muddy bottoms, while other 

 kinds of animals such as crabs, annehds, 

 etc., find shelter between the sheUs or in 

 their interstices." Thus VerriU and Smith 

 saw certain of the interrelationships that 

 exist on an oyster bank. 



A few years later Mobius (1877) wrote 

 of these in greater detail; his much-quoted 

 passage wiU be repeated here (from the 

 1883 translation) both because of its his- 

 torical significance and because of its dis- 

 tinctly modem tone. 



"Every oyster-bed is thus, to a certain de- 

 gree, a community of living beings, a coUection 

 of species and a massing of individuals, which 

 find here everything necessary for their growth 

 and continuance, such as suitable soil, sulficient 

 food, the requisite percentage of salt, and a 

 temperature favorable to their development. 

 Each species which lives here is represented 

 by the greatest number of individuals which 

 can grow to matiu-ity subject to the conditions 

 which surround them, for among all species 

 the number of individuals which arrive at ma- 

 turity at each breeding period is much smaller 

 than the number of germs produced at that 

 time. The total number of individuals of all 

 the species living together in any region is the 

 sum of the survivors of aU the germs which 

 have been produced at all past breeding or 

 brood periods; and this sum of matured germs 

 represents a certain quantum of Hfe which 

 enters into a certain number of individuals, and 

 which, as does all life, gains permanence by 

 means of transmission. Science possesses, as yet, 

 no word by which such a community of living 

 beings may be designated; no word for a com- 

 munity where the sum of species and individ- 

 uals, beings mutually limited and selected un- 

 der the average external conditions of life, 

 have, by means of transmission continued in 

 possession of a certain definite territory. I pro- 

 pose the word Biocoenosis for such a com- 



