234 BURRELL. 



must have been urine, but I am not sure now that the Echidna does exude urine; 

 I have never witnessed the action in the many specimens I have handled. 



LINKS IN THE LIFE HISTORY OF THE PLATYPUS. 



The observations noted in this paper were made principally during the most 

 severe "Spring" drought recorded in the North-western portion of New South 

 Wales. The deductions submitted may therefore have to be modified should 

 turther investigations be carried out during a bountiful season. 



Platypus usually select a quiet part of the river tor breeding purposes, 

 ■which need not necessarily be a deep or long pool such as they are usually found 

 ici at other times of the year in search of food and freedom. In the Manilla 

 District, an ideal natural nesting site is a shaded pool with steep sloping banks of 

 suitable soil, preferably black or red, which is reinforced with the roots of River- 

 Oak trees (Casuarina), and margined with reeds. Female platypus appear to 

 shun one another during the breeding season, since only once have 1 discovered 

 two occupied breeding burrows opening into the same pool. Even in that in- 

 stance, the burrows were separated by a distance of fully a quarter of a mile, and 



Flo. 3. — Plan of platypus burrow containing four nests, Nl, N2, N3, N4. At X, the burrow 

 passes a foot below its earlier level. 



they were placed in opposite banks of the river. Higher up the river, where both 

 male and female platypus were comparatively plentiful, we systematically searched 

 both sides of the river for a distance of eight miles ,but failed to find one in- 

 habited burrow. We waded the whole distance, and searched the banks from 

 lelow the water level to the tops above, and although we cut out the tunnel of 

 several entrances that we discovered, including those of Water Rats (Hi/dromt/s), 

 all proved to be ancient ami dilapidated, and the contained remnants of nesting 

 material appeared as though they had been submerged, being just a musty, sodden 

 mass, embedded in silt or "platypus pug." 



Although platypus prefer soft soil to burrow into, T once found a burrow 

 where three inches of river shingle had been removed from the face of the bank 

 at the entrance before the soft soil was reached. This stratum of shingle had evi- 

 dently once been the temporary bed of the river. 



A point I have been unable to determine is whether a platypus occupies the 

 same burrow for more than one season. With the exception of one extraordinary 

 case described below, T have never observed more than one nest in any burrow. I 



