ON THE NEW-GUINKA MAMMALS. 167 



looking at the innumerable new species described in the 

 last years, growing so to say every day, so that nobody 

 in the world can by any means keep all those names 

 in remembrance ! It never should be forgotten that Nature 

 knows no species, only individuals, and that in reality 

 there are no two animals nor two leaves of two trees exactly 

 alike! It is evident that individuals, belonging to a widely 

 distributed group of animals must be somewhat different 

 when living separated by high mountains, broad rivers or 

 wide seas, by living upon different food and under other 

 degrees of warmth ; in describing such a form — which we 

 may call a species — there should be observed and mentioned 

 as accurately as possible the difference in size and color, 

 constant or not constant, for every given locality ; in doing 

 so we become a true portrait of the animal; it is the way 

 followed iu my Monograph of the genus Cuscus (Notes 

 Leyden Museum, 1885), when I described separately every 

 individual. There hardly are two exactly alike — have we 

 therefore to bestow a latin or greec name to every indi- 

 vidual showing a slight — mostly a more or less — difference 

 in size or color? I think not. 1 may be allowed to illustrate 

 my view by an actual example. Take for instance our 

 Common Hare, Lepus europaeus Pallas, rather common 

 everywhere in our Fatherland ; now our huntsmen distinguish 

 specimens shot in the downs, in the sandy moors and on 

 pasture grounds as down-hares, heath-hares and grass-bellies — 

 and our epicures wholly agree with the huntsmen as they 

 can taste the difference — ; nay, the experienced hunters — so 

 one of them and friend of mine told me — see differences 

 between Rabbits from the downs near Katwijk and those 

 from near Zandvoort, a distance of about 26 miles! So 

 Hares living in Noord-Brabant can be distinguished from 

 those living in Holland, in Gelderland, in Friesland a. s. o.; 

 they all show peculiar characteristics in size and color 

 a. s. o. And all these characteristics are variable, so that 

 the Common Hare presents itself in the Netherlands under 

 perhaps six or more forms; and as our country cannot 



r>iotes from tlie Ijeyden JMuseuin, "Vol. XX"VIII. 



