496 
ASTRONOMY: CAMPBELL AND MOORE 
In conclusion, giant polar bodies do not develop because they are 
not fertilized and they are not fertihzed because they are generally 
formed after a spermatozoon has entered the egg and has rendered it 
impervious to other spermatozoa. 
REFERENCES 
Boveri, Th. (1887). Ueber den Anteil des Spermatozoon und der Teiking des Eies. 
Munchen, SiizBer. Ges. Morph., 3. 
(1891). Befruchtimg. Merkel «. Bonnet Ergehnisse 1. 
Francotte, P. (1898). Recherches sur la maturation, la fecondation et la segmenta- 
tion chez les Polyclads. Arch. zooL, Paris, 6. 
Hertwig, O. (1890). Vergleich der Ei- und Samenbildung bei Nem^atoden. Arch. 
mikr. Anat., Bonn, 36. 
Kostanecki, K. (1897). Ueber die Bedeutung der Polstrahlung, etc., Ibid., 49. 
Lefevre, G. (1907). Artificial Parthenogenesis in Thalassema mellita. /. Exp. ZooL, 4. 
Loeb, J. (1913). Artificial Parthenogenesis and Fertilization, Chicago. 
Mark, E. L. (1881). Maturation, Fecundation and Segmentation of Limax Compestris. 
Bull. Mus. Comp. Zool. Harvard, 6. 
Meves, Fr. (1911). Ueber die Beteiligung der Plastochondrien an der Befruchtung 
des Eies von Ascaris m.egalocephala. Arch. mikr. Anat., 76. 
(1912). Verfolgung des sogennanten Mittelstiickes des Echinindenspermiums 
im befruchteten Ei, etc. Ibid., 80. 
Platner, G. (1886). Ueber die Befruchtung von Arion Empiricorum. Ibid., 27. 
Sobotta, J. (1895). Die Befruchtung und Furchung des Eies der Maus. Ibid., 40. 
Ziegler, H. E. (1898). Experimentelle Studien ueber die Zellteilung. Arch. Entw. 
Mech., Leipzig, 6. 
RADIAL VELOCITIES OF THE PLANETARY AND IRREGULAR 
NEBULAE 
By W. W. Campbell and J. H. Moore 
LICK OBSERVATORY. UNIVERSITY OF CALIFORNIA 
Presented to the Academy, Seplemb« 10, 1915 
In a former number of the Proceedings^ one of the authors presented 
results on the radial velocities of 54 gaseous nebulae determined by 
spectrographic methods at the Lick and D. 0. Mills Observatories, 
working respectively in the northern and southern skies. It was there 
shown that the planetary nebulae, or those of regular form, are rapid 
travelers in comparison with the stars, a fact which casts serious doubts 
upon the generally accepted hypothesis that the stars have been formed 
from planetary nebulae by processes of evolution. 
During the past year observations at both institutions have been 
extended to fainter members of this class of objects, and there are now 
available some 348 measures of the velocities of approach and recession 
of 92 gaseous nebulae, or those whose spectra are composed of bright 
Unes. 
