A close inspection of the flowing tide as it swirls around our gratings reveals the presence of myriads of minute globular jellyfishes--the _cydippe pileus_--said to be the favourite food of the arctic whale, though one would scarcely expect these bulky cetaceans to thrive or even subsist on such watery diet. Ranging in size from a pin head to a walnut, what a gap each mouthful must make in their numbers. The poddlies themselves are not averse to this form of food, as they are occasionally seen to disgorge them when landed in our doorway. The common jellyfish progresses through the water with a pulsating movement of the entire disc, such movement being termed “pulmonigrade,” and somewhat resembles the action of an umbrella being partially opened and closed. The mode of progression in the case of the _cydippe_ is, however, different, and is termed “ciliograde,” as the propulsion is effected by means of eight vertical bands of cilia or minute plates overlapping each other. Each plate having an independent action of its own, the animal can propel itself in any desired direction, or, by resting them against its spherical body, sink to the bottom. In sunshine these animals in their evolutions emit the most beautiful combinations of colour one could imagine, but “you seize the flower, its bloom is shed”--scooped up in the hollow of the hand their beauty vanishes, and only a small spat of inert transparent jelly remains. Here at present in the Rock pools one may witness a peculiar phase in the evolution of the jellyfish. Along with many beautiful varieties of marine vegetation, miniature forests of fir trees garnish the bottom of each shallow pool. These lilliputian firs, with their branches no thicker than a hair, are but plants in semblance, for here is the opening chapter in the life history of the medusae. Under the lens each fragile shoot is seen to consist of multitudes of small discs piled upon each other like so many saucers, each of which will, in due course, detach itself from its neighbour and enter on its new existence as fully equipped as the exaggerated specimens frequently seen stranded on our beaches. Lurking amongst the vegetation in the pools are numerous tiny spider-crabs, roaming about in search of food. Only by their movements can they be located, as each bears about with it quite a luxuriant growth of vegetation, with which I understand all crustaceans would become invested did they not--ludicrous as it may seem--regularly attend to their toilet. The “spider,” however, unable to procure a living by force of arms like his bigger brother, has recourse to the subterfuge of posing as an innocent patch of marine vegetation, and by such concealment is enabled to capture food which would be otherwise unattainable. The females at present are seen to be carrying spawn. When changing their position in the pool it is somewhat surprising to see a portion of the plants, which one has been admiring,