Jaxuary 18, 1895.] 



SCIENCE. 



m 



certain surface markings never observed by 

 others. The opportunity given for examin- 

 ing the specimens, liowever, proved that the 

 markings could be faintly seen as described 

 by the author. 



Dr. Locy's second paper was a Note on the 

 Mumologies of the Pineal Sense-Organ. The 

 basis for determining homologies of the two 

 epiphysial outgi'owths of Petromyzon, Telc- 

 osts and Lacertilia has been furnished by 

 recent publications by Studuicka, Hill and 

 Klinckowstrom. Basing a comparison upon 

 innervation and also upon the history of 

 the vesicles, we may regard the upper epi- 

 physial vesicle in I'eti'omyzou as corres- 

 ponding to the epiphysis of Teleosts and 

 Lacertilia, and the lower epiphysial vesicle 

 as equivalent to the anterior vesicle of Hill 

 (which early absorbs ) in the teleosts. and to 

 the pineal eye in the Lacertilia. 



Under the title : • The Qiiadrille of the 

 Centrommes' in the Echinoderm egg; a second 

 contribution to biological mythology, Professor 

 E. B. AVilsou, of Columbia, presented the 

 somewhat surprising results of his renewed 

 investigation of the phenomena of fertiliza- 

 tion in the eggs of the sea-urchin. Rabl 

 had predicted in 1SS9 that the union of the 

 germ-cells would be found to involve a con- 

 jugation of centrosomes or archoplasmic ele- 

 ments in addition to the well-knowna conju- 

 gation of nuclear elements. Fol's celebrated 

 paper on the Quadrille of the Centrosomes 

 in 1891 was apparently a triumphant fulfill- 

 ment of the prediction, and, having been 

 ininiediatelj" and universally accepted, ex- 

 ercised an important influence on the current 

 theories of inheritance. A prolonged re- 

 search upoii the eggs of Toxopnenstes variegatus 

 shows, with a high degi-ee of certainty, that 

 Fol's results were based on material pre- 

 ))ared by defective methods; that his ac- 

 count of the origin of the archoplasm is 

 fundamentallj' erroneous ; that no ' Quad- 

 ri lie ' occurs in the American species at least , 

 and that his account of it is largelj' mythical. 



Results e.ssentially similar and fully corrob- 

 orating the above have been reached in the 

 Columbia Laboratory bj" Mr. A. P. Mathews 

 in the eggs of Arbucia and Asterias. In all 

 these cases the egg-centrosome and archo- 

 plasm degenerate and completely di.siippear 

 after formation of the second polar body, 

 and, therefore, do nut i>lay any part in the 

 fertilization. Tlie sperm-archoplasm is de- 

 rived not from the tip of sperm l)ut from the 

 middle-piece (as in the earth-worm and in 

 the axolotl) and by division gives rise di- 

 rectly to the amphiaster of the first cleavage 

 without any participation of an egg-centre 

 or egg-archoplasm. All the stages in the 

 fertilization process of Toxojmenstes were ex- 

 hibited by the author in photographs taken 

 ■with an enlargement of one thousjind ilia- 

 meters with the coiJperation of Dr. Edward 

 Leaming, of the College of Physicians and 

 Surgeons, Kew York. These photographs 

 illustrated furthermore the effect upon the 

 egg of various reagents, a considerable num- 

 ber of which have been carefully tested. 

 Fol's picro-osmic mixture was shown to be 

 very defective, causing more or less marked 

 disorganization of the archoplasmic struct- 

 ures and producing various artefacts. The 

 ' centei-s ' (centrosomes) of Fol were un- 

 questionably such artefacts, produced by the 

 slu-inking and clotting together of the ar- 

 choi)lasmic recticulum. In properly pre- 

 served material (sublimate-acetic, Flem- 

 ming"s fluid, etc..) the arehoplasm-masses 

 (' astrospheres') consist of a uniform reti- 

 culum and contain no centrosomes. 



In a second paper on the ^Polarity of the 

 Egg in Toxopneusfes ' Professor AVilson de- 

 scribed the results of his observations on 

 the paths of the jironuclei in tiie transpar- 

 ent li%Tng egg. The very unexpected result 

 was renehed that in this ca.se the ultimate 

 vertical axis of tlie egg (' egg-axis ' jn-opei-) 

 does not necessarily coincide with the polar 

 axis but may form any angle with it: but 

 the plane of first cleavage is nevertheless 



