322 



SCIENCE. 



[N. S. Vol. VII. No. 16S. 



distinguished from yolk granules at first, as, for 

 some time, no ' male' aster appears. Later, 

 however, the sperm-head enlarges and an aster 

 and centrosome appear, the centrosome divides 

 and two asters are formed connected by a spin- 

 dle. All of these disappear, however, at the 

 same time as the female aster and centrosome. 

 When the two pronuclei come into contact 

 no centrosomes or asters are visible in the egg. 

 The two pronuclei as a whole form the center 

 of a large radiation extending nearly to the 

 periphery of the egg. A little later a very mi- 

 nute centrosome and aster appear on each side 

 of the pronuclei in the copulation plane. Both 

 centrosomes and asters increase in size, one be- 

 ing larger than the other (the first cleavage is 

 unequal), fibers extend past the pronuclei from 

 one centrosome to the other and the first oleav 

 age spindle is formed. The pronuclei elongate 

 and lose their membranes without preceding 

 fusion. As the astral rays elongate, the radia- 

 tion which surrounded the pronuclei disappears 

 and the cytoplasm rearranges itself as the rays 

 of an aster centering about a centrosome. 



C. M. Child. 



Notes on the Peripheral Nervous System of Mol- 

 gula Manhatiensis. The intra-vitam method of 

 methylene blue staining was used. Sensory cells 

 occupying a lateral position in the endostyle 

 were found. These cells are characterized by 

 a distal knob or spike and one or more proxi- 

 mally placed enlargements, one of which con- 

 tains the nucleus. Some cells showed proto- 

 plasmic (?) branchings. No supporting cells 

 were seen. Nerve fibrils, after leaving the 

 epithelium, turn sharply at right angles to run 

 longitudinally as separate fibrils or in loose 

 bundles. They probably reach the (brain) 

 ganglion by the circumbuccal nerves. 



The endings in the branchial basket are knob- 

 or disk-like. Nerve fibrils may end on cells in 

 the walls of the branchial bars or freely. Fibrils 

 may lie in the supporting tissue or be applied to 

 the base of the epithelium, and, singly or in 

 bundles, anastomose to form a true plexus. 

 Ganglion cells are found. Fibrils end on the 

 basal part of mucus or ciliated cells in club or 

 disk-shaped endings. Other fibers touch the 

 base of a cell with a knob-like varicosity and 



continue their course, touching neighboring 

 cells in like manner before finally ending. 



A sub-epithelial plexus was found in other 

 parts of the body. Nerve endings were found 

 in the muscles and ciliated funnel. The sen- 

 sory nature of the tentacles and papillae of the 

 peribranchial sac was not demonstrated. 



G. W. Htjntek, Je. 



DUEING the two months the following reviews 

 and papers were also given : ' Recent Literature 

 on the Embryology of Insects' (Uzel and Hey- 

 mons). Dr. W. M. Wheeler ; ' The Lithodidse, 

 a Family of Asymmetrical Crabs,' S. J. Holmes ;. 

 'Theories of Animal Phosphorescence,' Dr. 

 Watase ; ' Some of the Functions and Features 

 of a Biological Station,' Dr. Whitman ; ' Recent 

 Literature on Regeneration ' (Joest), W. H. 

 Packard ; ' A Review of Some Recent Work on 

 Spermatogenesis ' (Bardeleben), M. F. Guyer ^ 

 ' Experimental Work on the Cilnophore Egg' 

 (Eischel), Dr. Child ; ' The Pronephros in 

 Teleosts ' (Felix), Miss E. R. Gregory. 



TOKEEY BOTANICAL CLUB. 



At the annual meeting, January 10, 1898,' 

 cash balances to the favor of the Club were re- 

 ported by the Treasurer and the Editor. 



The Recording Secretary, Professor Burgess, 

 reported au average attendance of 35 at the 1& 

 meetings held during the year, one death, a 

 present active membership of 213, correspond- 

 ing membership of 153, honorary membership of 

 4, total 370. Thirty scientific papers have been 

 presented. 



The Editor, Dr. Britton, reported the regular 

 monthly publication of the Bulletin, including^ 

 592 pages, 33 plates and 1 portrait ; and the 

 publication of Vol. VI., No. 2, of the Memoirs^ 

 containing 80 pages, issued July 30, 1897. 



Dr. Small reported for the Field Committee 

 that field meetings were arranged for every 

 Saturday from April 24th to October 30th, and 

 also on election day — 29 excursions in all. Thesfr 

 were usually half-day excursions, with 4 of the 

 whole day and 4 of two days each. They have 

 extended into the neighboring mainland of New 

 York, into Long Island, Staten Island, New 

 Jersey and Pennsylvania. The average attend- 

 ance upon the excursions was about 16, and the 

 average number of plants specially recorded 48. 



