136 LECTUEES ON BIOLOGY 



Leverrier, the Director of the Paris Observatory, determined the 

 place in which this planet would have to be looked for ; and when 

 Galle in 1846 directed his telescope to this spot he actually dis- 

 covered the planet Neptune. The Evolution Theory enables us 

 to make similar prophecies. The discovery by Goethe of the 

 human intermaxillary bone is a case in point. I have already 

 mentioned the ues centrale of the carpus which is present in 

 reptiles and amphibians but absent in man. If our view concern- 

 ing the descent of man from lower animal ancestors is correct 

 we are justified in assuming that a rudimentary ues centrale exists 

 in an early evolution stage of man. In point of fact it was dis- 

 covered in a human embryo by Kosenberger. 



Investigations made into various species of Hawk-moth 

 caterpillars (Sphingida) led Weismann to believe that the simple 

 longitudinal stripes in the caterpillars of the Humming-bird 

 hawk-moth (Macroglossa stellatorum) are phylogenetically older 

 than the more general spots or oblique stripes, because cater- 

 pillars thus marked developed from earlier forms with longi- 

 tudinal stripes. If this assumption was correct it was equally 

 applicable to other Sphingidae caterpillars with oblique stripes, 

 and Weismann predicted that the then still unknown earlier 

 forms of the Privet Hawk-moth (S. ligustri) possessed longi- 

 tudinal stripes. A decade afterwards the English zoologist 

 Poulton succeeded in demonstrating that the young caterpillars 

 actually possessed the postulated longitudinal stripes. 



[Recently the advances made in biochemistry have supplied 

 valuable corroborative evidence of the theory of phylogenetic 

 relations. It is a remarkable fact concerning the blood of two 

 different animals that the red blood corpuscles of one individual 

 are destroyed by the blood plasm of the other. Decomposition 

 becomes more difficult in proportion as the relation of the species 

 becomes more distant, whilst in closely related animals or in 

 individuals of the same species no injurious effects are observed. 

 After numerous experiments Friedenthal proved that the blood- 

 serum of man destroys the red corpuscles of the baboons and 

 mandrills, but not those of the anthropoid apes. Conversely, the 

 red corpuscles of man were in most cases decomposed by the 

 serum of the lower monkeys, but remained entirely unaffected by 

 the blood of the higher apes. 



