SUMMARY OF RESULTS 



THE work of the Expedition on Tardigrada has resulted in the enumeration of 

 fifty species, distributed in five genera. This may seem a small number, considering 

 how many countries were visited, and the great range of climatic conditions which 

 they present, from tropical heat to polar cold. 



These fifty species are, however, about half of the known Tardigrada, and 

 considerably more than half of the land and fresh-water species. And in addition to 

 the fifty species identified, a considerable number more (something like twenty-three 

 species) were observed and described, which, while not sufficiently known to be 

 identified or pronounced to be new, are recognised as distinct from any of the species 

 in the list. 



It must be remembered, too, that it is only within the last few years that 

 naturalists have begun to discriminate the species of Tardigrada carefully, and to 

 realise that they are fairly numerous. For half a century after the discovery of the 

 first water- bear by Go'ze in 1773 naturalists supposed that there was only one, or at 

 most two, species. From Schultze's time (1834), when Tardigrada began to be more 

 carefully looked at, for another half- century, scarcely a dozen species were dis- 

 tinguished. Even in 1888 Plate's monograph (23) admitted only twenty-five species, 

 in six genera. Eight of the species and two of the genera were Plate's own 

 discoveries. One of his genera, and at least four of his species, would now be 

 disallowed. 



Only with the arrival of Richters in the beginning of the present century were 

 the Tardigrada looked at with sufficient care, and satisfactory diagnoses inaugurated. 

 About the same period it began to be appreciated what great facilities were afforded 

 by mosses for the collection and study of microfaunas, and in consequence the 

 Tardigrada and other microscopic animals of distant countries became known. 



Among the Tardigrada collected by the Expedition there are seventeen species 

 recognised as new to science, and one new generic type was found in Australia. 



In the accompanying table is given a list of all the species collected, and their 

 distribution is shown in all the countries visited, and also the distribution over the 

 world. 



Distribution. An analysis of the list brings out some interesting facts. There 

 were observed in all 73 species, of which 33 were identified as known species, 17 are 



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