ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 143 



foundation for the statement made by Danilewsky that lecithin has a 

 marked effect in accelerating growth. When the experiments are per- 

 formed with sufficient care, it is seen that lecithin has no appreciable 

 effect whatever on growing animals. 



Occipital Condyles and the Origin of Mammals. * — Prof. H. F. 



Osborn favours the view that Mammalia may have arisen from some un- 

 known member of the Anomodont or Theriodont reptile stock, liis 

 present contribution relates to the condyles, four types of which are 

 recognised: — (1) typical monocondylic, in which the exoccipitals have 

 no share ; (2) tripartite monocondylic, in which the exoccipitals share ; 

 {3) trausitional dicondylic, chiefly exoccipital but partly basioccipital ; 

 and (4) typical dicondylic, in which the basioccipital element is cartila- 

 ginous or reduced in the median line. His conclusions are : — (a) unlike 

 reptiles, no mammals have the basioccipital projecting backwards as far 

 as the exoccipitals ; (b) nevertheless the participation of the basioccipital 

 in the condylar articulation is a common feature, and the Monotremes 

 present some grounds for considering this a primitive mammalian 

 feature ; (o) the weight of evidence is in favour of derivation from a 

 tripartite type with a depressed basioccipital. The reptilian tripartite 

 origin is more probable than the amphibian dicondylic origin. 



Papillary Lines on the Foot.f — Dr. Ch. Fere has made a study of 

 these in imbecile, epileptic, insane, and paralytic subjects, confirming 

 his conclusion J (in regard to the hand) that the figures are originally 

 related to movements of the skin rather than to pressure, and that they 

 are congenital characteristics practically invariable in the life of the 

 individual, but differing in each particular case. 



Claws on Birds' Hands.§ — E. Eegalia gives lists showing the occur- 

 rence of claws : — 59 forms have a claw on digit I., 10 have a claw on 

 digit II., and 72 have claws on both I. and II. 



Change of Colour and Moult in Birds.|| — Jonathan Dwight, jun., 

 has made an elaborate investigation of the Passerine birds of New York, 

 in order to solve the problem whether, as many believe, change of colour 

 can take place without moult. He finds that " every feather developes 

 with a definite colour and pattern, which it retains, modified only by 

 wear, until the next moult." This has hitherto been doubted only because 

 the subject of niuult has not been adequately studied. When a sufficient 

 series of birds of known age and sex is studied, it becomes obvious that 

 every species has a definite series of plumages and moults, that the 

 moults — the seasons of periodical feather-growth — may be complete or 

 incomplete, and that they are modified by age, sex, and even by individual 

 variation. All cases of apparent colour change not explained in this 

 way are due to wear, i.e. to passive destructive changes. 



Flightless Birds. f — Dr. J. Wigglesworth took this as the subject of 

 his inaugural address to the Liverpool Biological Society, and divides 



* Amer. Nat., xxxiv. (1900) pp. 943-7 (3 figs.). 



t Journ. de l'Anat. Physiol., xxxvi. (1900) pp. 602-18 (18 figs.). 



t Tom. cit., pp. 376-92 (14 figs.). 



§ Atti Soo. Tosc. Sci. Nat, xii. (1900) pp. 111-27. 



|| Aim. New York Acad. Sci., xiii. (1900) pp. 73-160 (7 pis.). 



If Trans. Liverpool Biol. Soc., xiv. (1900; pp. 1-33. 



