460 



PSYCHE. 



[May 1893. 



us in looking for important revelations 

 in other descendants of annelid-like 

 forms. Taking the embryo as our main 

 guide in determining questions of 

 primitive number and arrangement, we 

 find the possible hypotheses on the 

 Malpighian vessels to be quite limited ; 

 since in no insect embryo have more 

 than three fairs of these vessels been 

 found. 



Gegenbaur* observed the frequent 

 recurrence of the number two (some 

 times expressed only in the common 

 openings of numerous vessels) through- 

 out all the divisions of the Arthropoda. 

 Hence this number, he concludes, may 

 be regarded as primitive. It is obvious 

 that this statement may be correct for 

 the Arthropoda in general and still in 

 no wise conflict with the view that the 

 ancestor of a particular subgroup may 

 have had more than two Malpighian ves- 

 sels. Thus Protentomon may have had 

 several pairs and these, if ascertainable, 

 might be regarded as constituting the 

 typical number for the Hexapoda. The 

 remote ancestor of Protentomon may 

 have had but a single pair. 



Two views have been advanced as to 

 the number of Malpighian vessels in 



* 1. c. p. 292. 



Brief Notes. — Thorell has just published 

 a second octavo volume of about 500 pp. on 

 the spiders of Indo-Malesia. It is devoted 

 to the lower groups, and closes with a 

 table of the geographical distribution of the 

 462 spiders so far known from that region. 



Our students of Neuroptera will be grate- 

 ful to Nathan Banks for his Synopsis, cata- 

 logue and bibliography of the neuropteroid 

 insects of temperate North America just 



primitive insects. Paul Mayer,* in his 

 well known treatise, expressed himselt 

 very clearly on this subject. After 

 doing full justice to all the facts at his 

 disposal he concludes: "Dass die 

 anzahl der paare bei Protentomon 2 

 betrug, ist so gut wie sicher." The 

 embryological evidence accumulated in 

 1S76 was perhaps too meagre to lead to 

 any other conclusion. 



In two recent papers Cholodkowskyf 

 advances the opinion that the primitive 

 number of Malpighian vessels in insects 

 is two. He bases his conclusions on 

 some very interesting observations, to 

 which I shall have occasion to revert, 

 when I come to consider the Lepidop- 

 tera. 



My own observations on the embryos 

 and larvae of several insects, together 

 with the facts recorded by other ob- 

 servers, lead me to the conclusion that 

 the ancestral number of Malpighian 

 vessels in insects was six. In other 

 words, Protentomon was not only 

 hexapodous but also hexanephric. 



* Ueber ontogenie und phylogenie der insekten. Jen. 

 zeitschr. natjnviss. 10 bd. 1S76, p. 142. 



f Surles vaisseaux de Malpighi chez les lepidopteres. 

 Compt. rendus. tome 98, p. 631-633, 18S4. Sur la mor 

 phologie de l'appareil urinaire des lepidopteres. Arch, 

 biol. tome 6, fasc. iii, 1SS7. 



issued in the transactions of the American 

 entomological society. The tables are very 

 simple and brief, perhaps erring in this 

 latter feature. 



Interesting recent papers on relationships 

 among butterflies will be found in Spuler's 

 Zur stammgeschichte der Papilioniden (Zool. 

 jahrb., vi, 34 pp., 2 pi.), and Haase's Ent- 

 wurf eines naturlichen systems der Papilioni- 

 den (Bibl. zool., heft, viii, 120 pp., 8 pi.). 



