204 MISCELLANEOUS OBJECTIONS TO THE 



lated beak of a duck ? Ducks, like whales, subsist by sift- 

 ing the mud and water ; and the family has sometimes been 

 called Criblatores, or sifters. I hope that I may not be 

 misconstrued into saying that the progenitors of whales did 

 actually possess mouths lamellated like the beak of a duck. 

 I wish only to show that this is not incredible, and that the 

 immense plates of baleen in the Greenland whale might 

 have been developed from such lamellae by finely graduated 

 steps, each of service to its possessor. 



The beak of the shoveller-duck (Spatula clypeata) is a 

 more beautiful and complex structure than the mouth of a 

 whale. The upper mandible is furnished on each side (in 

 the specimen examined by me) with a row or comb formed 

 of 188 thin, elastic lamellae, obliquely beveled so as to be 

 pointed, and placed transversely to the longer axis of the 

 mouth. They arise from the palate, and are attached by 

 flexible membrane to the sides of the mandible. Those 

 standing towards the middle are the longest, being about 

 one-third of an inch in length, and they project fourteen 

 one-hundredths of an inch beneath the edge. At their 

 bases there is a short subsidiary row of obliquely transverse 

 lamellae. In these several respects they resemble the plates 

 of baleen in the mouth of a whale. But toward the ex- 

 tremity of the beak they differ much, as they project in- 

 ward, instead of straight downward. The entire head of 

 the shoveller, though incomparably less bulky, is about one- 

 eighteenth of the length of the head of a moderately large 

 Balaenoptera rostrata, in which species the baleen is only 

 nine inches long ; so that if we were to make the head of 

 the shoveller as long as that of the Balaenoptera, the lam- 

 ellae would be six inches in length, that is, two-thirds of 

 the length of the baleen in this species of whale. The 

 lower mandible of the shoveller-duck is furnished with 

 lamellae of equal length with these above, but finer ; and in 

 being thus furnished it differs conspicuously from the lower 

 jaw of a whale, which is destitute of baleen. On the other 

 hand, the extremities of these lower lamellae are frayed into 

 line bristly points, so that they thus curiously resemble 

 the plates of baleen. In the genus Prion, a member of the 

 distinct family of the Petrels, the upper mandible alone is 

 furnished with lamellae, which are well developed and pro- 

 ject beneath the margin; so that the beak of this bird 

 resembles in this respect the mouth of a whale. 



Fl'Pm the highly developed structure of tfre shoveller's 



