ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 617 



100 c.cm. of which had been added 1"2 c.crn. of N/10 NaOH solution. 

 Moore's method was to wash eggs of Strongylocentrotus purpicratus in 

 3/8 M sodium chloride solution for five minutes, then transfer to 3/8 M 

 strontium chloride solution for three minutes, and then put in sea water 

 containing spermatozoa of Arbada ochracea. Within half an hour 

 25 p.c. of the eggs had formed membranes ; 10 p.c. of these segmented 

 regularly and formed blastulge. 



Permeability of Sea-urchin Ova by Stains.* — J. Runustrom finds 

 that the permeability of the ova of Parcchinus mUiaris for methylen- 

 blue and neutral red is lessened by the maturation. The blue penetrates 

 much more slowly than the red into the ripe unfertilized egg. After 

 fertilization or the artificially induced formation of a membrane, the 

 permeability for methylen-blue increases again, though not to the same 

 degree as before maturation. The permeability by neutral red is much 

 the same after fertilization, but the rate is slightly lessened. 



Minute Structure and Regeneration in Crinoids. t — August 

 Reichensperger gives a histological account of Pe)itacriiius decorus, 

 dealing with the dorsal nervous system and its branches, the fibrous 

 connexions'of parts, the ventral musculature, the chambered organ, the 

 calcareous matrix, and the sacculi. He also deals in the regenerating" 

 arm with the closure of wounds, and the degeneration of cell-elements, 

 the water- vascular svstem and coelome, the dorsal and ventral nervous 

 system, the genital strand, the cirri, and the influence of variotis factors 

 on the growth of the arm. 



Histogenesis of Synapta.J — K. Reiraers has studied the develop- 

 ment of Synapta digitata, starting with the auricularia larva. He deals 

 with the nerve-strands, the flat epithelium, the mesenchyme, the 

 calcareous bodies, the musculature, the gut, and the coelome. The 

 transformation into the barrel-shaped form is described, and the trans- 

 formation of the latter into the young Synapta — all with especial 

 reference to histogenesis. 



Study of Phyllophorin8e.§ — Hiroshi Ohshima has studied the mode 

 in which the tentacles of these Holothuroids spring from the radial 

 canal, the number of the tentacles (15-30 in two or three whorls), the 

 distribution of pedicels and papillae, and the very varied calcareous 

 deposits. 



Coelentera. 



Nervous System of Acraspeda.|| — H.Jordan has studied this as an 

 example of what he calls " poor in reflexes " — a neuromuscular system 

 of the lowest order. He finds that the locomotor musculature has no 



* Arkiv f. Zool., vii. (1911) No. 13, pp. 1-17. 



t Zeitschr. wiss. Zool., c. (1912) pp. 1-69 (4 pis. and 9 figs.). 



X Jen. Zeitschr. Naturw., xlviii. (1912) pp. 263-314 (2 pis. and 12 figs.). 



§ Ann. Zool. Japon, viii. (1912) pp. 53-96 (1 pi. and 7 figs.). 



II Zeitschr. wiss Zool., c. (1912) pp. 116-38. 



