The Development of Admelus pumilio Koch; 

 a Contribution to the Embryology of the Fed i palps 



BY 



Introduction. 



I began my investigations of the development of A d- 

 metus pumilio in November 1899. During the previous 

 year I had been studying the development of spiders under 

 Prof. A. Groette, in Strassburg. 



Through the kindness of Prof. R. Burckhardt I re- 

 ceived, materials to examine, which he had obtained from 

 Dr. Goeldi in Para. These materials consisted of two fe- 

 males ofAdmetus pumilio each of which carried a batch 

 of eggs, which will be described under Stages II and V. 



In January, 1900, I received two further batches of 

 eggs, this time through the kindness of Dr. Gr. Hagmann, 

 also in Para ; unfortunately only one of these batches was of 

 use ; from it I procured Stages I, II, and IV ; the other 

 had been deserted by the mother animal, as Dr. Hagmann 

 stated. Cuts through embryos coming from this batch 

 only show an inner mass of yolk surrounded by a thick 

 and dense layer of bacilli. I was not able to procure any 

 further material. 



At this place I must also express my thanks to Prof. 

 F. Zschokke, Director of the Zoological Institute of the 

 University of Basle, in whose laboratory this paper was 

 prepared, and to Prof. R. Burckhardt, to whom I am much 

 indebted for the help he rendered me during my studies, 

 and more especially whilst working at this paper. 



I must also express thanks publicly to Dr. Groeldi 

 and Dr. Hagmann for having procured me the materials, 

 and to my friend and fellow- student Oskar Huber, for 

 some of the drawings given in this paper. 



