BY J. J. FLETCHER AND A. G. HAMILTON. 359 



the Muclgee district on one occasion found a cluster of ten under 

 a piece of wood, and on another occasion twenty-four cocoons from 

 all but one of which however the young had hatched. These were 

 the capsules of G. quinqueliyieala, the only species of which we 

 have yet seen the newly-hatched young, but we have a few 

 cocoons of other species which are still under observation. The 

 cocoons met with vary slightly in size and shape ; usually they 

 are spherical, and 3 or 4 mm. in diameter ; others have one axis 

 longer than the other, about 5x3 mm. When freshly de- 

 posited they are yellow or orange-coloured, but in the course of 

 a day or two the colour changes to a dark reddish-brown or 

 even black. The number of young which come out of a cocoon is 

 about three or four. In two instances the young hatched out in 

 five weeks or a day or two longer, after the deposition of the 

 cocoons. The latter usually rupture and when empty collapse, 

 but in one case the young emerged from a small circular hole 

 without the cocoon rupturing or collapsing. Sometimes the 

 cocoon ruptures a few days before the animals leave it ; at other 

 times they come out very soon after. The newly-hatched young 

 of G . qidnquelineata, vary slightly in size, from 2*5 to 4 mm. long 

 and 1*5 mm. wide, or even longer when fully extended ; they are 

 striped just as are the adults, except that the outermost stripe on 

 each side is either very faint, or altogether absent ; both stripes 

 and ground-colour are in some cases brighter and pinker than is 

 usually the case in adults, but the colours are extremely variable 

 in this species, though it is perfectly well characterized, by its five 

 dorsal, linear stripes. As yet we have not met with the young 

 ones of any other species. 



In addition to the sexual mode of reproduction, planarians 

 frequently divide spontaneously by transverse fission into portions 

 which are capable of acquiring the characters of complete animals. 

 Mr. Darwin gives an interesting account of an experiment he 

 made with one of the Tasmanian planarians, which he cut into two 

 nearly equal halves ; these, in the course of twenty-five days, 

 were all but indistinguishable, when the increased heat on 

 approaching the equator put a stop to his observations (Voy. of a 



