358 ANNUAL OF SCIENTIFIC DISCOVERY. 



M. Berthe tells us that butter, olive, poppy, almond, and whale oils, Eng- 

 lish cod liver oil, cod liver oil washed or discolored with alkalies and charcoal, 

 and pure brown cod liver oil, were all successively administered by him to 

 one man in good health, and under a regular diet, in doses increasing from 30 

 to 60 grammes during the day. By an exact daily determination of the 

 quantity of oil contained in the faeces, he ascertained the average number of 

 days necessary to arrive at complete saturation, that is, when the whole of 

 the fatty body was found in the excrements ; for poppy, almonds, and olive 

 oils, twelve days ; for butter, whale oil, and English cod liver oil, decolored 

 or washed, about a month; while pure brown cod 'liver oil administered for 

 a month, failed to produce any perceptible increase in the fatty matter of the 

 excrements. Whence M. Berthe divides the fatty bodies into three classes, 

 based on their powers of assimilation. 



1st Class. Bodies difficult of assimilation : Poppy, almonds, and olive 

 oils, and probably all the vegetable oils. 



2d Class. Assimilable bodies: Butter, whale oil, white, washed, or 

 decolored cod liver oils, and probably all the animal fats. 



3d Class. Yery assimilable bodies: Brown and pure cod liver oil. 



VIVIPAKITY AND OVIPAKITY. 



At the American Association Albany meeting, Professor Agassiz made a 

 communication on viviparitjr and oviparity, which his researches in embry- 

 ology have thrown great light on. At one time it was believed that those 

 animals which brought forth their young alive, had peculiarities which indi- 

 cated exclusive relationship. The progress of embryology had proved that 

 there was no such relationship, and no radical difference between viviparous 

 and oviparous animals. In the family of snakes there were viviparous and 

 oviparous genera. The vipers bz'ought forth their young alive, but they were 

 no more like quadrupeds for all that. Among quadrupeds, too, the marsu- 

 pials, when first born, were carried about by the mother, attached to the nip- 

 ple, until they were capable of being born again, and standing on their OWH. 

 legs. Placental connection between mother and young was of no consider- 

 able consequence. Sharks showed that some oviparous, though sharks had 

 not many eggs like most fishes, but few and large in proportion to their size, 

 as those of a hen ; some viviparous without placental connection and some 

 with. Yet the mode of development in all three was precisely the same, 

 and was a shark development. There was nothing in it which was allied to 

 that of birds in animals. This had a decided influence on classification. 

 There was no reason for separating the marsupials from other mammals. In 

 each group and different class the relation between the modes of develop- 

 ment indicated the real relations of the animals. Animals which were de- 

 veloped in the same manner were sure to be found in the end to belong 

 to the same general division. He would maintain this, that the distinc- 

 tions founded on complications of structure must be given up for general 

 classification, and confined to the minor distinctions. This was a modifica- 

 tion of the system of Cuvier, but he trusted that we should not much longer 

 be compelled to depend on complications of structure for general divi- 



