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ARABIAN NEMATODES. 



By N. A. Cobb. 



In the winter of 1888-9, I collected, among other things, on 

 the coast of Arabia, about two hundred marine Nematodes, an 

 examination of which discovers seven specific forms. The marine 

 Nematodes hitherto studied, those of Carter excepted, have been 

 taken from European branches of the Atlantic Ocean, ^.e.,the Baltic, 

 North and Mediterranean Seas. It is therefore of interest to find 

 that all the species in my Arabian collection can be referred to 

 known genera inhabiting Atlantic waters. I afterwards observed 

 some of these forms living on coasts of the Southern and of the 

 Pacific Oceans, as well as on other coasts of the Indian Ocean. 

 The geographical range is therefore roughly indicated. Various 

 structural facts here recorded will, I think, be found of interest 

 by those familiar with the Nematode anatomy. 



Methods. 



Nematodes are to be sought (1) among marine and fresh- water 

 algae, (2) in sand and mud at the bottom of water not too stagnant, 

 (3) in moist earth especially about the roots of plants, (4) on and in 

 the higher plants, and (5) in the greatest variety of animals, where 

 either as facultative or obligate parasites they are often the cause 

 of specific diseases of the most serious kind. 



In the hope of stimulating yet closer examination into the 

 structure and life-histories of the free-living Nematodes by 

 showing how easily and in what super-abundance the necessary 

 material may be obtained, I detail here the methods I have found 

 useful. These methods apply to a host of other minute organisms, 

 all less frequently studied than they would be if better ways of 

 securing and investigating them were known. 



