20 ELEVENTH REPORT. 



1. How can [a character acquired during senility be transmitted to 

 offspring which are born l^efore the character is acquired, and still the 

 offspring develop the senile characters of the parent. 



2. Neo-Darwinians have formulated the following test for the transmis- 

 sion of acquired characters. If a form is placed in a new environment it 

 will freriuentl}' develop new characters, but if the offspring even of the third 

 or fourth generation, which has the new characters, be transferred back to the 

 original environment the characters assumed during the changed condition 

 will disappear. The acquired characters were not fixed. Lamarckism has 

 not yet pointed to an undoubted case of the fixity of accjuired characters. 



3. Experimenters can not say whether the characters which appear under 

 changed conditions are new or whether they are reversions to a previous 

 condition when the animals lived in an environment similar to the one in 

 which it is jjlaced by the experimenter. 



4. Lamarckism can not explain the growth and development or rudi- 

 mentary structures. It cannot account for the development of characters 

 which are useless. 



Now having rejected other explanations what has the Neo-Lamarckian 

 to offer instead. I fear that he comes with little bu.t a wealth of observation 

 and a receptive mind. He has observed long phyla in which characters ap- 

 pear, not fortuitously, so far as w^e can see, but deter minately , in the place 

 where thev will at some future stage do the most good to the animal. He 

 has observed such characters or structures appear as useless rudiments, 

 persist as such during the life of the individual and gradually develop to 

 usefulness during the life of the race. He has observed these rudiments 

 rise and develop entirely removed from the influence of the environment. He 

 feels that he must minimize the effect of both Ontogeny and Environment 

 in the formula proposed and there is only left the effect of heredity (H) 

 and an X. For Selection is a constant factor in all. 



Let us consider the strongest case which the Neo-Lamarckian has to offer; 

 that of the molar teeth of the mammals. 



1. Teeth do not appear as developing organs exposed to the influence 

 of the environment but attain full perfection in the individual beneath 

 the gum and only break through to reach any contact Avith the environ- 

 ment when fully formed. 



2. Immediately upon exposure to the environment the contract works to 

 the detriment of the tooth because the wear continuously lessens the 

 efficiency of the tooth. 



No one can see the direct effect of either a Buffonian or a Lamarckian factor 

 here. The tooth is developed free from any contact with the environment 

 ^nd the effects of use are distinctly to reduce the value of the structures. 

 The inheritance of a retrograde character such as this last would not afford 

 material for selection. 



Paleontologists have worked out the plan and order of the appearance 

 of the cusps on the molar teeth of the mammals and l^rought the law to such 

 perfection that it has stood the final test of successful prophecy. This is 

 definite evolution such as was foreshadowed by the founders of the Neo- 

 Lamarckian school when Hyat in 1866 wrote concerning the Cephalopods. 

 "In other words there is an increasing concentration of the adult characters 

 in the young of higher species and a consequent displacement of embryonic 

 features which had themselves also appeared previously to the adult period 

 of still lower forms," and Cope in the same year wrote "The presence of a 

 rudimental condition, or the absence of a given generic character can be 



