ON THE VICTORIAN LAND PLANARIANS. 67 



the body only (Figs. 3, 3a). All these stripes may be more or less suppressed, the 

 first to disappear being those on the outside and the last the one in the middle ; or 

 we may with equal justice assume that the parent form had no stripes and that the 

 first to appear was the median one and the last the outside ones. The observations 

 of Fletcher and Hamilton on the markings of very young specimens of Geoplana 

 quinquelineata, which will be found quoted in the description of that species, seem to 

 indicate that the latter assumption is the correct one. So it is in most of the species; 

 the markings, if there are any, may be more or less strongly emphasised in different 

 individual specimens, but fimdamentally the pattern is the same in all. I have 

 pointed out* the same fact in the case of Peripatus leuckartii. 



We now know a good deal about the general habits of land Planarians. They 

 are what I have elsewheref termed " Cryptozoic" animals, living for the most part 

 under logs and stones, or the dead bark of trees. They prefer moderately damp 

 situations and appear to be much more abundant in the autumn, after rains, than in 

 the drought of summer. When at rest in their hiding places they commonly lie 

 coiled up with the anterior extremity in the centre of the coil (Fig. 12). As a rule 

 they seem to venture abroad in search of food at night only, or in very damp weather, 

 but I have more than once found Geoplana sugdeni crawling about in broad daylight, 

 once on a stone near the top of Mount Macedon, in a decidedly dry situation. 

 Geoplana lucasi, again, was obtained by Professor Spencer at a height of 4000 feet 

 on the top of the coast ranges in the Croajingolong district. 



Still there can be no doubt that land Planarians require a very considerable 

 amount of moisture for then- existence. Thus I once found a considerable number 

 of specimens which had escaped from the collecting box dried up on the floor of a 

 room, having apparently exhausted all their supply of moisture in the production of 

 their slimy'track. 



In this connection I may mention that when a living land Planarian is placed 

 in loose dry earth, it forms a cyst for itself by cementing together the particles of 

 earth with its slimy secretion. Within this cyst the Planarian hes completely 

 hidden, but if the cyst be torn it will crawl out perfectly clean and free from earth. 

 This habit of formmg cysts of earth may be a protection against drying up and may 

 perhaps account for the disappearance of land Planarians in the heat of summer. 



Land Planarians crawl with an even, gliding motion, which I believe to be 

 largely due to the action of the numerous strong cilia on the ventral surface, for I 

 have seen a minute fragment of the worm, snipped off with a pair of scissors, 

 gliding away over a smooth surface by itself, much as in the case of detached parts 



♦ Proceedinga of the Koyal Society of Viotorin ; 1880, p. 50, el seq. 

 t Victorian Naturalist ; December, 1889. 



