638 SUMMARY OF CURRENT RESEARCHES RELATING TO 



forwards into an aorta ; posteriorly it is attached by fine fibrils to 

 the tergal region of the body ; no posterior orifice was to be detected ; 

 there are five pairs of ostia, and five pairs of alary muscles. The 

 cardiac tube consists of a plexiform nucleated tissue, broken through 

 at various points ; then follows a well-developed muscular layer which 

 forms the chief part of the tube, and internally to it there is a delicate, 

 hyaline, and structureless layer. The blood is of a yellowish-red colour, 

 and contains a fairly large number of blood-corpuscles. They have a 

 clear, homogeneous ground-substance with dark refractive granules, 

 and no investing membrane ; they exhibit amoeboid movements. 



The author was unable to find any traces of a visceral nervous 

 system or of nervi transversi ; the absence of the latter may be asso- 

 ciated with that of a tracheal system. Sensory setae are to be observed 

 on the legs, palps, and labium and labrum. 



The generative organs are carefully described, and there are some 

 remarks on ecdysis; the author found that Gregarines, Cysticerci, and 

 a number of Nematoid worms lived parasitically in Macrotoma. 



iS. Ilyriopoda. 



Latzel's Myriopods of Austria.* — The first volume of Dr. R. 

 Latzel's work dealt with the Chilopoda, while the second includes the 

 Symphyla, Pauropoda, and Diplopoda. Nine years of close attention to 

 the study of the Myriopods have enabled Dr. Latzel not merely to 

 complete a monograph of the species inhabiting his native country, 

 but to complete it in such a manner that he has written a book which 

 must be useful to the student of the Myriopoda of any country. 

 Minute descriptions of some 170 species are given, and also tables 

 which make it a matter of ease to determine the genus of any 

 Myriopod. 



Where possible, full descriptions are given of the young stages of 

 each species, and the results of all recent researches into the minute 

 anatomy of the Myriopods are embodied. Embryology, indeed, has 

 not received a very large share of attention, but references are given 

 to all writings on the subject. Dr. Latzel differs from some American 

 authorities in looking on Scolojpendrella as a true Myriopod, and 

 places its order Symphyla as intermediate between the Chilopoda 

 and the Pauropoda. Dr. Latzel agrees with Menge in considering 

 those organs which Eyder has described as trachea in Scolopendrella, 

 as being merely chitinous supports for muscle-attachment. These are 

 the same organs which Wood-Mason considers to be of the nature of 

 segmental organs. 



Dr. Latzel looks on Peripatus as forming an order equivalent to 

 other orders, the Chilopoda, the Symphyla, and the Diplopoda. 



A most useful bibliography, brought down to the date of publica- 

 tion, is comprised in the work, f 



* Latzel, K., * Die Myriopoden der Oesterreichisch-Ungarischen Monarchie,' 

 2te Halfte, xii. and 413 pp. and 16 pis., 8vo., Vienna, 1884. 

 t See Nature, xxxi. (1885) p. 526. ' 



