G52 CHORD AT A. 



for want of a better name Caucasians, with straight or wavy hair and 

 lighter complexion. Hero belong the Hamosemites, the Aryans or Indo- 

 Germans, Nubians, and Dra vidians (primitive inhabitants of India). 



Since an arboreal life was unfavorable for fossilization, the paleontolog- 

 ioal material for the history of the primates is so far very scanty. Of 

 these the greatest weight has been laid on a 'find' in the upper pliocene 

 of Java. This consisted of a top of a skull, a femur, and a molar tooth 

 which were found at some distance from each other, making it doubtful 

 whether they belonged together. These fragments were regarded on one 

 side as a connecting link, AnthroxM'pWiecus erectus, between apes and man, 

 on another as belonging to a true ape, and from the third as true man. 

 The latter is now to be regarded as out of the question. Most probable is 

 the view that these pieces belonged to an extinct gibbon-like animal of 

 extraordinary size, an enormous cranial capacity and correspondingly a 

 very large brain. In these respects no Anthropoid now living could com- 

 pare with AnfJiTojmjntJiecus. 



Summary of Important Facts. 



1. The CHOEDATA are imited Ly the ijossession of an axial 

 skeleton, the notochord, lying between the nervons system and the 

 alimentary tract; a central nervous system entirely on one side of 

 the digestive canal, and gill slits extending from the 23harynx to 

 the exterior. 



2. The Chordata are subdivided into Leptocardii, Tunicata, 

 I^hiteropneusta, and Vertebrata. 



3. The LEPTOCAEDII are fish-like in form, have a notoehord 

 extending the length of the body, bi;t lack skull and vertebral 

 column ; the brain is rudimentary, the gill slits numerous. 



4. The TUNICATA have a notoehord only in the caudal 

 region. The young is tadpole-like, but in most forms there is a 

 metamorphosis iu which tail and notoehord are lost. 



5. The body is usually enclosed in a tunic or mantle containing 

 cellulose, gill slits and an endostyle are piresent in the pharynx, 

 the heart changes in the direction of the flow of blood. The nerv- 

 ous system in its development is tubular and connects with the 

 digestive tract by a neurenteric canal. In the Salpida^ there is a 

 typical alternation of generations between a solitary asexual and a 

 sexual chain form. 



G. The ENTEKOPNEUSTA are worm-like, with collar and 

 liroboscis; a diverticulum of the digestive tract is compared to the 

 notocliord; gill slits occur in the pharynx; some undergo a meta- 

 morphosis iu develojuncnt, the larva resembling those of Echino- 

 derms. The ])ertinenee of the Enteropneusta to the Chordata is 

 not certain. 



