TITLES. 
Gen. Sub. 37 
576. P&CHOUTRE, F. La cellule. Annee biol. vii, pp. xi-xviii. 
577. . Les produits sexuels et la fdcondation. T. c. pp. xviii-xxii. 
578. . Morphologie et physiologie g<$n£rales. T. c. pp. xxxiii-xlvi. 
With an appendix on cytotoxins by Szczawinska, pp. xlvi-lvi. 
579. Peebles, F. A preliminary note on the position of the primitive 
streak, and its relation to the embryo of the chick. Biol. Bull, iv, 
pp. 211-214. 
580. Peel, C. V. A. The zoological gardens of Europe, their history and 
chief features. London, 1903, 8vo, xiv 4-256 pp., pis. 
581. PjEsrez, C. Sur la resorption phagocytaire des ovules par ies cellules 
folliculaires, sous l’influence du jeune chez le Triton. Pr.-verb. Soc. 
Sci. Bordeaux 1903, pp. 73, 74. 
582. . Resorption. Triton . C.R. Soc. Biol. 1903, pp. 716-718. 
583. . Contribution h l’etude des metamorphoses. Bull. Sci. France 
Belgique xxxvii, pp. 195-427, pis. x-xii. 
Recorded last year, without being seen, from a separate copy [Zool. 
Rec. xxxix, Gen. Sub. (632)]. 
584. Perrier, E. La Tachygen&se ou acceleration embryogenique. C.R. 
Ac. Sci. cxxxvi, pp. 798-801. 
585. — - & Gravier, C. Sur les causes physiologiques qui ont determine 
la constitution du type Mollusque. T. c. pp. 727-731. 
586. Peter, K. Bemerkungen zur Entwickelung der Eidechse. Anat. 
Anz. xxiv, pp. 156-164. 
587. . Mitteilungen zur Entwicklungsgeschichte der Eidechse. iv 
& v. Die Extremitatenscheitelleiste und die Anlage der Mitteldarm- 
drusen. Arch. mikr. Anat. lxi, pp. 509-536, pi. xxv. 
588. Petersen, C. G. J. & others. De Danske Farvandes Plankton i 
Aarene 1898-1901. Danske Selsk. Skr. xii, No. 3, pp. 223-326. 
589. Petersen, W. Entstehung der Arten durch physiologische Isolierung. 
Biol. Centrbl. xxiii, pp. 468-477. [Lepidoptet'a.] 
590. Petrunkewitsch, A. Das Schicksal der Richtungskorper im 
Drohnenei. Ein Beitrag zur Kenntnis der naturlichen Partheno- 
genese. Zool. Jahrb. Anat. xvii, pp. 481-516, pis. xi-xiii. 
Abstract by Fick, Zool. Zentrlbl. x, pp. 563, 564. 
591. *Petschenko, B. Uber Veranderungen im Bau des Kernes bei 
Paramoecium in naturlichen Existenzbedingungen. Rabot Lab. 
Warsaw, Heft xxx, 1903. 
In Russian, cf. Zool. Zentrlbl. xi, p. 509. 
592. Pfluger, E. Ueber die jungfrauliche Zeugung der Bienen. Arch, 
ges. Physiol, xcix, pp. 243, 244. 
593. Phillips, Everett F. A review of parthenogenesis. P. Amer, Phil. 
Soc. xlii, pp. 275-345. 
Includes a valuable bibliographical list, pp. 315-345. 
. [See also Casteel & Phillips (115).] 
594. *Piepers, C. Mimikry, Selektion und Darwinismus. Leiden, 1903, 
452 pp. 
Criticism, Allg. Zeitschr. Ent. viii, pp. 505-507. 
