ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 449 



Characese there is indirect nuclear division at the vegetative point, 

 while the nuclei of the growing internodal cells multiply by direct 

 constriction. In these two, as in many other cases among plants, 

 direct nuclear division is not accompanied by division of the cell, and 

 herein they agree with such cases of direct nuclear division as have 

 been observed in animal cells. The relations of direct to indirect 

 cell-division require much further investigation. 



Developmeiit of Chelifer.* — M. J. Barrois publishes some obser- 

 vations upon the larval condition of Chelifer. The number of limbs 

 is five pairs ; all the future limbs exist, but they are incompletely 

 developed and of no functional use ; the nutritive yolk is encircled 

 by a layer of exodermic cells, and in front is a suctorial stomach ; 

 this latter is an organ peculiar to the larva, and is shed when it at- 

 tains to maturity ; the nervous system consists of two bands, one 

 behind and another in front of the suctorial stomach ; when the latter 

 is got rid of they become fused. 



Descriptions of New Acarina.t — Dr. Gr. Haller describes some 

 new American species of the genera Tyroglyphis, Oribata, and 

 Eremceus ; from Europe he describes anew species of DamcBus and 

 of Cheyletia, and a remarkable new genus, which he calls Michaelia 

 [M. paradoxa), dedicating it to Mr. Michael, in recognition of his 

 great services to the Oribatidee specially, and to Acarinology generally. 

 Standing near Hoplophora, it is remarkable for the character of the 

 lamelliform structures found on its appendages, and over the whole 

 surface of the body ; in M. paracloxa they are generally lancet- 

 shaped ; their wide distribution over the body leads to the supposition 

 that they are sensory organs, but time alone will show whether this 

 view as to their function is correct. The only species known is of 

 some size (1 mm. long), of a bright brown colour, and is found rarely 

 among decaying vine-roots in Germany. 



Sphserogyna ventricosa.J — Prof. A. Laboulbene and M. P. Megnin 

 give an account of this Acarid, which has been placed with Heteropus 

 and with Physogaster, but for which they institute a new genus. 



The female is ovoviviparous, and gives birth to adult males and 

 females, which are fecundated at once ; all development is intra-uterine. 

 This is the first example of such a phenomenon among the Arthro- 

 pods, and perhaps in any zoological group. In the uterus one can 

 distinguish males from females, and there is here no question of 

 parthenogenesis. In the embryonic condition, and immediately after 

 birth, there is a blackish residue in the intestines, but as soon as 

 the Acari begin to suck the juices of their prey, these juices appear 

 to be absorbed completely, and leave no residue. They have a 

 poisonous salivary secretion, which is the chief cause of the death of 

 the insects on which they feed ; it is secreted by four pairs of vesicles 

 which are set along the oesophagus, and is emitted immediately aftei' 

 the insertion of the lancet-like mandibles. 



* Comptes Rendus, xcix. (1884) pp. 1082-3. 

 t Arch. f. Naturgesch., 1. (1884) pp. 217-36 (2 pis.) 

 X Journ. Anat. et Physiol. (Robin), xxi. (1885) pp. 1-17 (1 pi.). 

 Ser. 2.— Vol. V. 2 G 



