Within the group of islands which together comprise Spitsbergen outcrops of dolerite may be traced over an area of about 50,000 square miles. The area is doubled if the neighbouring dolerites and basalts of Franz Josef Land are included. Even so, this is but a part of a network widely spread over the north-western part of the Euro-Asiatic continental platform, and over adjoining circumpolar lands. The sill-swarms of Spitsbergen alone rival in extent any of approximately similar age in other parts of the world, such as those of South Africa, South America, India, Antarctica, or North Britain. They merit a great deal more attention than it has yet been possible for geologists to devote to them.

Present knowledge of the oogenesis of caddis-flies is scanty. Marshall's paper (17) on the ovary of Platyphylax designatus is the only detailed account of the growth and history of the ovarian elements during the larval and pupal stages, but he does not deal with the cytoplasmic inclusions.

I. Term Representation of Diatomic Spectra.

The mathematical symbolism now employed by the practical spectroscopist for the representation of the energy term F(J) of the diatomic molecule has recently been fixed with precision as a result of the labours of Mulliken and others. The formula employed to represent the rotational term is

where J is the quantum number and Be, De, … are constants. BeJ(J + 1) is the kinetic energy, expressed in wave-numbers, which the molecule would have if it were a rigid rotator; and the remaining small correction terms in powers of J(J + 1) correspond to the expansion of the rotator under centrifugal force.