|5() Beard, On the Occurrence of Dextro-rotatory Albumins in Organic Nature. 



Smith, Geoffrey. 1912. Studies in the experimental analysis of sex. Part 9. 



On spermatogenesis and the formation of giant spermatozoa in Hybrid Pigeons. 



Quart. Journ. Micro. Sci. 58: 159170. pi. 8. 

 Stomps, Theo J. 1911. Kernteilung und Synapsis bei Spinacia oleracea L. 



Biolog. Centralbl. 31: 257-309. pis. 3. 



1912 a. Die Entstehung von Oenothera gigas de Vries. Ber. d. d. Bot. 



Gesellsch. 30: 406416. 



1912 b. Mutation bei Oenothera biennis L. Biolog. Centralbl. 32: 521 535. 



pi. 1. fig. 1. 



Strasburger, Eduard. 1910. Chromosomenzahl. Flora 100: 398446. pi. 6. 

 Tahara, M. 1910. Uber die Zahl der Chromosomen von Crepis japonica Benth. 



Bot. Magazine 24: 2327. pi. 2. 

 Tischler, G. 1910. Untersuchungen iiber die Entwickelung des Bananen-Pollens. I. 



Arch. f. Zellforsch. 5: 622670. pis. 3031. figs. 4. 

 Wiemen, H. L. 1910. A study of the germ cells of Leptinotarsa signaticollis. 



Journ. Morphology. 21: 135207. figs. 73. 

 Wilson, Malcolm. 1911. Spermatogenesis in the Bryopliyta. Annals of Botany. 



25: 415457. pis. 3738. figs. 3. 

 Wilson, E. B. 1909. Studies on chromosomes. IV. Journ. Exptl. Zool. 6: 6999. 



pis. 2. figs. 2. 



On the Occurrence of Dextro-rotatory Albumins 



in Organic Nature. 

 By John Beard D. Sc., Edinburgh. 



Twenty-four years ago the discovery of a transient nervous 

 apparatus in the developmental histories of certain fishes directed 

 my attention to the problems of alternation of generations in general, 

 and of antithetic alternation in particular. Research in the inter- 

 vening years was devoted mainly to the unravelling of the thread 

 of animal development regarded as based in such an antithetic 

 alternation of asexual and sexual generations. A review of the 

 problems, which occupied the investigator during these years, and 

 of their solutions, cannot be given here: the finds are recorded in 

 the literature of science and most of the salient points may be 

 found in detailed form in the memoirs, cited below 1 ). These com- 



1) Beard, J. The History of a Transient Nervous Apparatus in certain 

 Ichthyopsida: An Account of the Development and Degeneration of Ganglion-Cells 

 and Nerve-Fibres, Parti. Raja latis, in: Zool. Jahrbiicher, Morph. Abteil., Vol.8, 

 with eight Plates, 1896. 



idem. On Certain Problems of Vertebrate Embryology, Jena, Gustav 

 Fischer, 1896. 



idem. The Span of Gestation and the Cause of Birth, Jena, Gustav Fischer, 1897. 



idem. A Morphological Continuity of Germ-Cells as the Basis of Heredity 

 and Variation, in: Review of Neurology and Psychiatry, Vol. 2, 1904. 



idem. The Enzyme Treatment of Cancer, London, Chatto & Windus, 1911. 

 See also Hay don, W. T. The "Biogenetic Law" considered in relation to an 

 Antithetic Alternation of Generations in the Metazoa, in : 26th Annual Report of 

 the Liverpool Science Students' Assoc, 1907, 



