870 RECORD OF CUKRENX RESEARCHES RELATING TO 



Differences between the Young and the Adult Forms of the 

 Gamasidse.* — Dr. Kramer's paper on this subject deals especially 

 with the criticisms of M. Megnin, who stated (1) that the abseoce of 

 the holding lobes from the anterior pair of feet was peculiar to females 

 and nymph-forms, (2) that the dorsal shield was only cleft in nymphs, 

 and (3) that the margin differs in form in nymphs and in the different 

 sexes. Kramer, however, is by no means satisfied as to the accuracy 

 of these views, and he states that he has only observed in a single 

 species the absence of the holding lobes, that he has had under 

 observation adult females of species of Gamasus in which the dorsal 

 shield has been divided, while as to the characters of the margin, 

 howsoever they vary, the variation is not such as to render their 

 specific characters obscure. 



Pairing of Spiders."]" — The Eev. H. C. McCook describes minutely 

 the pairing of a male and female of Linypliia marginata which he 

 witnessed in June, 1878. The observation is too long for our space, 

 but it may be mentioned that the pair were in union for 2 hours 

 and 55^ minutes, dui-ing which period they were separated nineteen 

 times in consequence of various interr aptions, some of which could be 

 accounted for, but others were apparently without any extraneous 

 cause. Twice the male ran to one side of the dome, made a web 

 attachment to a bit of leaf hanging in the snare, drew out a thread 

 about 2^ inches long, which he overlaid a couple of times, and then 

 made the following motion : First, the body was placed erect, i. e. 

 back upward, and was moved backwards and forwards along the line, 

 rubbing the points or " nippers " of the palps at the same time ; then 

 the spider swung over until the body made an angle of about 45° with 

 the line, and while holding on thus the palps were rubbed back and 

 forth alternately along the lino as before. The process was repeated 

 during another of the intermissions. It was conjectured that the 

 purpose of this movement might be the distribution of the seminal 

 fluid into the palpal bulbs. This is takeu up by the sacs, by the 

 inflation and contraction of whose membranous coats it is forced into 

 the spermathecae of the female. 



Observations on the Pycnogonida.J — Nearly ten years ago Dr. 

 Dohrn published in the ' Jenaische Zeitschrift ' an essay on the 

 structure and development of the Pycnogonida, which he was led to 

 place with the Arachnida, rather than with the Crustacea, on account 

 of the presence of seven pairs of appendages ; the three pairs found 

 in the larva were seen to be converted into the maxillary palpi, 

 antennfe, and accessory or ovigerous feet ; as to the last it was shown 

 that they were formed at the same time as the first pair of true legs, 

 and that therefore there could be no relation between them, in the 

 way of one being developed from the other. 



Professor Semper has lately been investigating the history of the 

 same group, and has come to certain conclusions § with which we will 



* ' Arch. Naturg.,' xlv. (1879) p. 238. 

 t 'Proc. Acad. Nat. Sci. Philad.,' 1879, p. 150. 

 j • Mitth. Zool. Stat. Noapel,' i. (1878) p. 28. 

 § ' Arbeit. Zool.-zoot. Inst. Wiirzburg, i. p. 264. 



