CONTRIBUTIONS TO OUR KNOWLEDGE OF THE ANATOMY 

 AND RELATIONSHIPS OF SPIDERS. 



Alexander Petrunkkvitch, Ph. D. 

 INTRODUCTORY REMARKS. TERMINOLOGY. 



Walckenaer may have been right when in 1837 he pointed 

 with pride to the long list of works on spiders already in existence 

 and said that if Pallas could only see it, he would surely no 

 longer reproach naturalists for neglecting this interesting group 

 of animals. Unfortunately the reproach of Pallas may be 

 repeated now more justly than ever before. It is true that a 

 quantity of excellent work has been published since the time of 

 Walckenaer, much more and much better work than before. But 

 the group remains a neglected one especially if compared with 

 such favorites as insects or vertebrates. When two years ago 

 I began to gather material for a manual on spiders I soon became 

 aware that our knowledge of their anatomy and embryology is 

 entirely inadequate. Not only the nervous system and the 

 sense organs, but even the external sexual organs from which 

 the characters for the identification of species are chiefly derived 

 need thorough re-examination. This sad discovery stimulated 

 me to new research and the present series of articles is a result of 

 it. I shall omit all reference to literature which will be exten- 

 sively treated in the manual I hope to be able to complete and 

 to publish some day. Only such papers will be mentioned as are 

 absolutely necessary to the understanding of the subject. More- 

 over to avoid loss of time and to make the reading easier I shall 

 describe things as I found them during my investigations, with- 

 out making constant mention as to what is new and what was 

 already known. Those who know the literature will easily sep- 

 arate the new from the old, while those who are not so well 

 acquainted with it will be glad to have the subject treated in a 

 short and comprehensive manner. I need scarcely add that 

 everything described by me in the present series of articles is 

 based on careful and extensive study. 



Concerning the methods I have applied during my investiga- 

 tions I have little to say. They are the ones commonly used by 

 zoologists and anatomists, i. e., dissecting with the aid of scissors, 

 scalpels and needles for macroscopic examination, at times aided 

 by in toto staining and injections ; mounting of whole spiders or 



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