236 



SCIENCE. 



[N. S. Vol. V. No. 110. 



•can be raised. Two cases are now known in 

 which the same thing is claimed for fertilized 

 «ggs {3Iyzostoma, Unio), and the work of Miss 

 Foot on the egg of Allolohophora fosHda suggest 

 that the so-called sperm-aster may not, after all, 

 be a derivative from the sperm. Mead's dis- 

 covery of numerous asters in the unfertilized 

 egg of Uhsetopterus suggests that these struc- 

 tures and the centrosome as well are but tran- 

 sient figures of the cytoplasmic network — figures 

 that may appear at any number of points of the 

 cell body on occasion. In that case their dis- 

 appearance would not indicate degeneration, 

 but merely a return to the reticular condition, 

 a resolution of figure rather than of substance. 

 This view would accord with the theory of the 

 centrosome advanced by Dr. Watase. 



The question as to which sex determines the 

 pace of development, or whether both sexes 

 share in this determination, is one for which it 

 is possible to find a crucial, experimental test. 

 My experiments are not yet concluded, but 

 they already furnish a decided answer to the 

 main question. The experiments are made bj' 

 crossing diflerent species of pigeons having 

 diflferent incubation periods. The crosses first 

 made, and the only ones thus far fruitful, were 

 between the common dove $ and the ring- 

 dove 9 (Turtur risorius). The incubation period 

 of the male species is from 18 to 20 days, while 

 that of the female species is from 14 to 15 days. 

 If the male furnishes the centrosome we should 

 expect to have the rate of development retarded 

 and the incubation possibly prolonged to the 

 time of his species. In the reverse experiment, 

 with a male T. risorius and a female common 

 dove (experiment now in progress), the rate 

 of development would be accelerated, and the 

 time of incubation correspondingly shortened. 

 One pair have hatched young three times, each 

 time in the period of the mother. A second 

 pair (^ = a fan tail) have hatched once, also in 

 the regular time of the mother. The young 

 birds were perfectly formed. 



These experiments show that the rate of cell- 

 formation and embryonic development up to 

 the time of hatching is determined by the sex 

 that furnishes the egg. Some marks of paternal 

 derivation are already visible in the newly 

 hatched hybrid, e. g., color of the beak and 



character of the down. The male influence is 

 most predominantly marked in the later de- 

 velopment and color of the plumage. 



C. O. "Whitman. 



BIOLOGICAL SOCIETY OF WASHINGTON, 270TH 

 MEETING, SATUKDAY, JANUARY 16. 



Theo. Holm showed the Society a botanical 

 work printed in the year 1549, in which bino- 

 mial nomenclature was in use. This book was 

 Leonhart Fuchs' Historie des Plantes, and it 

 was surprising to see that several of our com- 

 mon plant-names used to-day were also known 

 at that very early date, for instance : Vitis 

 vinifera, Aconitum lycoctonum, Angelica silves- 

 tris, Digitalis purpurea, etc. 



Mr. Holm also showed the first and the last 

 volume of the famous work 'Flora Danica,' 

 which contains illustrations of 3,240 plants 

 from Denmark, Norway, Sleswic, Fserce islands, 

 Iceland and Greenland engraved on copper. 

 This work was begun in the year 1761, the ex- 

 pense being paid by the Danish king until 

 1883, when the publication was brought to a 

 close. The botanical editors of the work were 

 Oeder, O. F. Mueller, M. and I. Vahl, Horne- 

 mann, Drejer, Schouw, Leibmann, Japetus 

 Steenstrup and Lange, while six Danish kings 

 contributed the funds necessary for the publi- 

 cation of this voluminous opus. 



Mr. Holm thereupon showed a specimen of 

 the interesting Draha hyperborea, which had 

 lately been collected by Mr. Macoun on the 

 Pribilof Islands. This species is not only of 

 gigantic size in proportion to the other species 

 of Draba, but it is also most characteristic in 

 having a monopodial ramification. The species 

 of Draba are generally annual, biennial or per- 

 ennial, but have constantly a terminal inflores- 

 cence. In Draba hyperborea, on the contrary, the 

 bud is terminal, but purely vegetative and lasts 

 for several years, while the inflorescences are 

 all lateral. A similar case was known to the 

 speaker to exist in Arabis dentata, which, in this 

 respect, showed a difference from most of, if not 

 all, the other species of Arabis. 



W. T. Swingle exhibited specimens of two 

 simple algse from the Gulf of Naples, remark- 

 able for the great size of the apicial cells. Al- 

 though very similar in appearance, these two 



