Pflueger.
Phillips.
Philosophy, influence of the conception of evolution on modern.
Phryniscus nigricans.
Phylogeny, embryology as a clue to.—Palaeontological evidence on.
Physiology of plants, development of.
Piccard, on Geotropism.
Pickering, spectroscopic observations by.
Piranga erythromelas.
Pisum sativum.