28 Mr. II. M. Bernaid on the 



to me to ignore the fact that both structures arise in similar 

 positions, Viz. at the bases of the hmbs. The tlioracic traehese 

 of Galeodes open posteriorly on the coxa of tlie second pair 

 of legs. In addition, then, to the extreme improbability of 

 the same structure — trachea} — having had two independent 

 origins in the same animal, we have the further improba- 

 bility that the openings of the assumed independently deve- 

 loped thoracic tracheae should bear apparently the same rela- 

 tion to the thoracic limbs as the lungs do to the embryonic 

 abdominal limbs. 



These arguments, I think, lend considerable support to my 

 attempt to deduce tracheas from setiparous glands. The first 

 two points seem to show that the lateral row of stigmata, 

 spinning-glands, &c. found in the Myriapoda and Hexapoda 

 have actually been deduced from the acicular glands of dorsal 

 parapodia, the ventral parapodia forming the legs. Such a 

 confirmation of this part of my original suggestion leads us 

 almost naturally to conclude that the ventral row of tracheae, 

 spinning-glands, &c. in the Arachnida have been developed 

 from the setiparous glands of the ventral parapodia. If so, 

 the legs of the Arachnids have been most probably developed 

 from the dorsal parapodia, Avhile the ventral parapodia have 

 disappeared in the coxal joints, their setiparous glands, how- 

 ever, persisting as trachea &c. This origin of the limb in 

 the xVrachnids is exactly what I have elsewhere endeavoured 

 to show must have been the origin of the legs of the Crus- 

 tacea. This would account for the great similarity between 

 the legs of Limulus and those of the Arachnids, and also for 

 their common possession of coxal glands. It would also 

 account for the traces of Crustacean characters found by 

 Jaworowski * in the developing limbs in the embryo of 

 Trocltosa singoriensis t- 



IV. — On the Terminal Or(jaa of the Pedipalp of Galeodes 

 and the Discovery of a Homologous Organ on the Pedipalp 

 of Phrynus. By Henry M. Beknakd, M.A. Cantab, 

 (from the Huxley Research Laboratory). 



The remarkable protrusible organ at the tip of the pedipalp 

 of Galeodes has, since Dufour's discovery, received but little 



• " Ueljer die Extremitattn, doreu Driisen, und Kopfsegmentirimg bei 

 Truchosa sintjuricmis" Zool. ^Vnz., May 18U2. 



t I regret to have omitted to meution in my former paper what had 

 been a very valniil)le work of reference to me, viz. Palm^n s *Zur Mor- 

 pholugie des Tracheensystems,' Leipzig, 1877, 



