S U M M A R I U M.

ascending and descending, are connected only through fibrils. Concerning their ducts or spiral wrinkles. The force, which is applied to the upper tendons, falls back onto the lower tendons. A small membrane, wandering through the muscles, protects the fibrils; so that if one is harmed, the neighboring ones are not harmed. Spiral ducts, or those wrapping themselves around, explained by a copper wire. Concerning the tendons of the haddock original: "Afelli majoris". Certain fishy fibrils everywhere fulfill the role of tendons. The eye of the haddock is examined.

Whether the beginning of motion is to be ascribed to the tendons or to the fibrils, the Author does not wish to define. Concerning the extension and contraction of a nautical rope. How much force that rope suffers in the middle, if force of 100 pounds is applied to the other extremity. The same is transferred to the tendons and fibrils. As often as a muscle is extended, the surrounding parts of the tendon, and also the fibrils, are also set into motion. Smaller animals have faster motions. Concerning the spiral ducts of the smallest birds. The tendons, in the foot of a river crayfish, are not worthy of that name. More concerning the tendons, fibrils, spiral figures, etc., of crabs and lobsters. Their fibrils are not unworthy of the name of muscles. Whether the filaments, from which their membranes are woven, are truly vessels, or should be considered as small nerves, is not sufficiently known to the Author. Nerves are composed of small cords.

Concerning the animalcules of male seed. Mr. Vallisnieri’s objections are refuted. The eggs of smaller fish are no smaller than the eggs of larger fish. Perhaps the animalcules of cetacean seed do not exceed in size the animalcules which swim in the seed of the smallest fish. Spiral ducts explained. All fibrils covered with membranes. The insertion of fibrils into the membranes of tendons. Whatever force is applied to an upper tendon, redounds into the lower tendon. Mr. Hartzoeker is criticized. Description of nerves.