486 



PSYCHE. 



[July 1S93. 



Haliday,* Meinertf andGrassii agree 

 in stating that Malpighian vessels are 

 absent in Iapyx. 



Opinions are divided as to the occur- 

 rence of Malpighian vessels in the Col- 

 lembola. Nicolet § thought he saw 

 three pairs in Podurids and figures 

 them in Podura similata. Frey and 

 Leuckart|| and v. Sieboldf also men- 

 tion six as the number in Podurids. 

 DeOlfers** saw only four in the Col- 

 lembola. 



On the other hand, Laboulbeneft and 

 FernaldJJ find no trace of Malpighian 

 vessels in Anurida maritima. Schin- 

 dlerjf § failed to find them in Podura 

 ardorea, and Lubbock|||| had no better 

 success with Orchesella fastuosa (a 

 species in which they were figured by 

 von Olfers), Tomocerus plumbeus, 

 Smynthiirus and other species. Tull- 

 berg's^HI results are also negative. 



*Japyx, a new genus of insects belonging to the 

 stirps Thysanura in the order of Neuroptera. Trans. 

 Linn. soc. vol. xxiv, 1864, p. 444. 



t On the Campodes, a family of Thysanura. Ann. 

 mag. nat. hist. vol. xx (3) 1S67, p. 372. 



t 1. c. p. 310. 



§ Recherches pour servir a l'histoire des Podurelles. 

 Nouv. mem. soc. helvet. d. sci. natur. 1841, p. 47 (pi- iv, 

 fig. 2). 



|| 1. c. p. 102. 



IT 1. c. p. 625. 



** Annotationes ad anatomiam Podurarum. Diss, 

 inaug. Berolini., 1S62, p. 16. 



tt Recherches sur l'Anurida maritima. Ann. soc. 

 ent. France. 4° ser. tome iv, 1S64, p. 715. 



tfl.cp.468. 



§§ 1. c.p. 602. 



||||Monograph of the Collembola and Thysanura. Ray 

 soc. London, 1873, p. 75. 



ITIISveriges Podurider. Kongl. svenska vetensk. akad. 

 Handlngar. bd. 10, no. 10, 1872, p. 22. 



The majority of recent writers, among 

 whom Oudemanns deserves special 

 mention, are of the opinion that the 

 Collembola have no Malpighian vessels. 



It is clear that no phylogenetic con- 

 clusions of any value can be drawn from 

 the heterogeneous observations here 

 given. After making all due allowance 

 for errors of observation, it is safe 

 to say that the Malpighian vessels 

 of the Apterygota are in a state of what 

 Baron v. Osten Sacken calls "morpho- 

 logical restlessness." The amplitude of 

 variation within the group is very great, 

 extending from twenty vessels in Machi- 

 lis to none in Anurida and allied forms. 

 There are grounds for believing that 

 this variation is not a precursor of ad- 

 vancing development, but rather an ex- 

 pression of degeneration. Other organs 

 — such as the eyes, tracheae, sexual 

 organs — show a similar great range of 

 structural variation and stamp the Ap- 

 terygota as a group which has well nigh 

 run its course in Hexapod evolution. 



Dermaptera. In Forjicula auricu- 

 lar ia according to Ramdohr,* there are 

 twenty Malpighian vessels, inserted in. 

 clusters of five on four protuberances of 

 the chylific gut. In the same species 

 Schindlerf found the number of vessels 

 to be greater than 30, and their inser- 

 tions, if I understand him correctly, to 

 encircle the gut regularly. 



* 1. c. p. 76. 



1 1. c. p. 604. 



