CHAPTER XIX 



TARDIGRADA 



OCCURRENCE ECDYSIS STRUCTURE DEVELOPMENT AFFINITIES- 

 BIOLOGY DESICCATION PARASITES SYSTEMATIC 



THE animals dealt with in this chapter lead obscure lives, remote 

 from the world, and few but the specialist have any first-hand 

 acquaintance with them. Structurally they are thought to show 

 affinities with the Arachnida, but their connexion with this 

 Phylum is at best a remote one. 



Tardk f rades are amongst the most minute multicellular 



O O 



animals which exist, and their small size averaging from 

 .', to 1 mm. in length and retiring habits render them very 

 inconspicuous, so that as a rule they are overlooked; yet Max 

 Schultze 1 asserts that without any doubt they are the most 

 widely distributed of all segmented anim;ils. They are found 

 amongst moss, etc., growing in gutters, on roofs, trees or in 

 ditches, and in such numbers that Sehult/e states that almost any 

 piece of moss the si/e of a pea will, if closely examined, yield 

 some members of this group, but they are very dillicult to see. 

 The genus Macrobiolvx especially affects the routs of moss growing 

 on stones and old walls. J/". macronyx lives entirely in fresh 

 water, and L//</e,lla d't>j ////!//. and Echiniscoides sigismundi are 

 marine; all other species are practically terrestrial, though in- 

 habiting very damp places. 



In searehing amongst the heather of the Scoidi moors for 

 the ova and embryos of the Nematodes which infest the ali- 

 mentary canal of the grouse, I have recently adopted a method 

 not, as tar as I am aware, in use before, and one which in every 

 i Arch. mikr. Anal. Hd. i., 1805, ]>. 

 477 



