PROGRESS OF MICROSCOPICAL SCIENCE. 109 



sjiiraciilar openings concentrated towards a more ventral line {lulus) 5 

 in otlierstliey took a more lateral position (Lepidopterous larvae, &c.). 

 A concentration along two lines of the body, ventral and lateral, has 

 already commenced in Peripatus. The original Protracheate being 

 supposed to have had numerous small trachefe diffused all over its 

 body, the question as to their mode of origin again presents itself. 

 The peculiar form of the tracheal bundles in Peripatiis, which consists 

 of a number of fine tubes opening into the extremity of a single short 

 common duct leading to the exterior of the body, seems to give a clue. 

 The tracheae are, very probably, modified cutaneous glands, the homo- 

 logues of those so abundant all over the body in such forms as Bipalium 

 or Hirudo. The pumping extension and contraction of the body may 

 well have dra^vn a very little air, to begin with, into the mouths of 

 the ducts ; and this having been found beneficial by the ancestor of the 

 Protracheate, further development is easy to imagine. The exact mode 

 of develoiDment of the tracheae in the present form must be carefully 

 studied ; there was no trace of these organs in the most perfect state 

 of Peripatus which I obtained. 



", Professor Gegenbaur's opinion on the i^osition of Peripatus* is, 

 that its place among the worms is not certain, but that, at any rate, it 

 connects ringed worms with Arthropods and flat worms. The general 

 result of the present inquiry is to bear out Professor Gegenbaur's 

 opinion ; but it points to the connection of the ringed and flat worms, by 

 means of this intermediate step, with three classes only of the Arthro- 

 pods — the Myriopods, Spiders, and Insects, i. e. the Tracheata. From 

 the primitive condition of the tracheae in lulus, and the many relations 

 between Peripatus and Scolopendra, it would seem that the Myriopods 

 may be most nearly allied to Peripatus, and form a distinct branch 

 arising from it and not passing through Insects. The early three-legged 

 stage may turn out as of not so much significance as supposed. If these 

 speculations be correct, the Crustacea have a different origin from the 

 Tracheata. Peripatus itself may well be placed amongst Professor 

 Hackel's Protracheata ; Grube's term, Onychophora, becomes no more 

 significant than De Blainville's Malacopoda. Some notions of the 

 actual history of the origin of Peripatus itself may be gathered from 

 its development. 



" In conclusion I would beg indulgence for the many defects in this 

 paper, due to the hurry with which it was written (all available time, 

 almost up to the last moment of our sailing for the Antarctic regions, 

 having been consumed in actual examination of the structure of 

 Peripatus), and due, further, to the impossibility of referring to original 

 papers in any scientific library. At all events it is hoped that Peripatus 

 has been shown to be of very great zoological interest, as lying near 

 one of the main stems of the great zoological family tree, and that 

 further examination of the most minute character into the structure of 

 this animal will be well repaid." 



Lesions of the Brain in General Paralysis. — Dr. J. Batty Tuke 

 gives the following instructive account of recent researches on this 



* ' Gruudzugc dor vcrglcicliciKku Aiiiituiiiie,' p. I'jy. 



I 2 



