946 



SCIENCE. 



[N. S. Vol. XII. No 312. 



this exceedingly interesting question, for so 

 far as I know the literature, not one case of 

 spore-formation has been carefully investi- 

 gated and most cases of parthenogenesis in- 

 sufficiently. And yet such investigations, 

 particulai'ly in the lower plants and animals, 

 would be a profitable and important work. 

 In my summary I have not mentioned 

 the budding and the fission of the multicel- 

 lular animals and the so-called ' vegetative 

 reproduction ' of plants. We commonly 

 unite these processes with the budding of 

 the Protozoa and the spore- formation of the 

 Algse, under the name of asexual reproduc- 

 tion. I have considered them only briefly 

 as new acquisitions of multicellular organ- 

 isms. In ' vegetative reproduction ' whole 

 multicellular stocks are set free from a 

 mother animal which has rapidly increased 

 in size. The phenomenon presents the 

 greatest diversity. The budding of the 

 Tunicates is quite different from that of the 

 Bryozoa or Hydroids or from the fission of 

 the Annelids. The diversity in the forms of 

 vegetative reproduction is still greater in 

 plants. The investigations in the past 

 twenty years have also proved that the 

 division and budding of the Metazoa do 

 not follow the laws laid down by the germ 

 layer theory. In this respect they resemble 

 regeneration. The whole matter will be a 

 self-evident phenomenon if we accept the 

 view of reproduction which I have set forth 

 above and recognize in the division and 

 budding of the multi-cellular animals adap- 

 tive phenomena which have come about in 

 the several groups independent of their de- 

 velopment. These processes of asexual re- 

 production are well jamed bj' the botanist 

 ' vegetative reproduction.' If they are more 

 common in the lower than in the higher 

 forms it is because the higher organization 

 sets a limit to the vicarious substitution of 

 one part for another. Similar conditions 

 therefore underlie vegetative reproduction 

 and regeneration and there are many anal- 



ogies between the two processes. It is 

 worth noticing that in the lower plants, 

 where spore-formation is very common, 

 ' vegetative reproduction,' if we use the 

 term as we have just defined it, is not 

 present. Stocks which have been acciden- 

 tally broken off from the threads of Algse 

 can, it is true, develop further, but under 

 natural conditions the Algse seldom make 

 use of the process for reproduction. 



WiNTBRTON C. Curtis. 

 Johns Hopkins University. 



STUDY OF THE COSBELATION OF THE HU- 

 31 AN SKULL* 



The substance of this paper was a thesis 

 for the London D.So. degree ; it was shown 

 to Professor Pearson, at whose suggestion 

 considerable modifications were made, aud 

 a revision undei'taken with a view to pub- 

 lication. 



In order to deal exactly with the problem 

 of evolution in man it is necessary to ob- 

 tain in the first place a quantitative appre- 

 ciation of the size, variation and correla- 

 tion of the chief characters in man for a 

 number of local races. Several studies of 

 this kind have been already undertaken at 

 University College. These fall into two 

 classes, (i) those that deal with a variety 

 of characters in one local race, and (ii) 

 those which study the comparative value of 

 the constants from a variety of races. Thus 

 Dr. E. Warren has dealt with the long 

 bones of the N"aqada race,t Mr. Leslie 

 Bramley-Moore has compared the regres- 

 sion equations for the long bones from a 

 considerable number of races in a memoir 

 not yet published, Professor Pearson has 

 dealt with the regression equations for 

 stature and long bones as applied to a 



* ' Data for the Problem of Evolution in Man,' 

 No. VI. By Alice Lee., D.Sc, with some assistance 

 from Karl Pearson, F.E.S. Abstract read before the 

 Royal Society of November 15, 1900. 



tP/i«. Trans., B, Vol. 189, p. 135. 



