228 NATURAL SCIENCE. ■ Sept.. 



by the intercalation of the families formerly separated as the anomalous 

 division Apetalae. Some of these, like the Chenopodiaceae and 

 Amarantaceae, fall naturally into their places, but the affinity of 

 others, like Salicaceae (the willows) is doubtful or quite unknown, 

 while others again comprise distinct series. Under each natural order 

 (the very rare or small ones are omitted) the most important charac- 

 teristics are given, with the floral formula and the broad geographical 

 distribution. In the case of larger orders, division into tribes is noticed, 

 in the smaller only the endemic genera and the species of economic 

 importance. 



Professor Packard on Acquired Characters. 



On the Inheritance of Acquired Characters in Animals with a Complete 

 Metamorphosis. By Alpheus S. Packard, M.D. Reprint from the Proceedings 

 of tit e American Academy of Arts and Sciences, 1894, pp. 331-370. Boston, Mass. 



The historical /rt'«5 with which Professor Packard opens his paper 

 very naturally consists largely of an exposition and criticism of 

 Weismannism. In this he makes one serious error. By quotations 

 from the " germ-plasm," he supports his statement that " Weismann's 

 reasons for not accepting the doctrine of transmission of acquired 

 characters would appear to be purely hypothetical and a priori.'" It 

 is certainly true that Weismann has adduced purely theoretical and 

 () priori reasons. But again and again in published papers he has 

 examined supposed cases of the transmission of acquired characters 

 and of mutilations, and has shown the considerations of actual fact 

 which support his hypothetical and a priori objections. As a matter 

 of history, each term in the continuous adduction of fresh cases, or 

 supposed cases, of such a transmission, has been brought forward after 

 Professor Weismann and his supporters have shown reasons for not 

 accepting preceding terms. The present position of the controversy 

 is this. As yet no case of the transmission of acquired characters has 

 been brought forward based on evidence accepted as cogent by 

 Professor Weismann and his supporters. Professor Packard may 

 say that this is so much the worse for the intelligence of Professor 

 Weismann and his supporters. He may not say that their reasons 

 are purely hypothetical and a priori. 



Professor Packard reviews a number of the arguments brought 

 forward by the advocates of this transmission and adds several of his 

 own. We are, however, compelled to state that the arguments are 

 not presented so as to convince any but the already convinced. Take 

 one of his instances. He cites Paul Bert's experiments upon daphnids, 

 in which he attempted to acclimatise these fresh-water Crustacea to 

 saline water by gradually adding salt. At the end of forty-five 

 days, when the water of the aquarium contained 1*5 per cent, of salt, 

 " all the Daphnise had died ; but the eggs contained in their brood- 

 sacs had survived, and the new generation of Daphniae, to which they 

 had given birth, flourished perfectly well in the same medium." " We 

 should interpret these facts," says the Professor, " as showing that 

 the crustacean had been so profoundly affected in the lifetime of the 

 individual as to produce young perfectly adapted to a changed 

 environment. The germ -plasm may have been the vehicle, all the 

 same, but the experiment is a case in favour of the neo-Lamarckian 

 principle." Was ever argument less cogent ? Here are animals 

 supposed to transmit to their offspring a character before they have 

 acquired it : to transmit to their eggs a capacity to endure salinity,. 

 to the non-acquisition of which they testify by their own deaths. 



