Antonii a Leeuwenhoek ... Epistolae physiologicae super compluribus naturae arcanis

LETTER XXI. Page 191

The common opinion, that the periwinkle original: "Vinca Pervinca" is not fertile with seed, is refuted as false. Follicles or seminal pods found in the periwinkle. The shell of that seed examined. The plantlet drawn from the periwinkle seed is described. Concerning the flour and oil included in the periwinkle plantlet. Other observations concerning the periwinkle.

LETTER XXII. Page 196

Why the Liege hop original: "Lupulus Leodiensis" is superior to our own. The willow-like leaves of the hop examined under a microscope, etc. The seeds of the hop contain nothing but the new plant. The leaflets of the seminal pod are covered with oily globules. The saline particles of those oils. The same oil abounds with flexuous and arched parts, etc.

LETTER XXIII. Page 206

ON membranes interposed between tendons, etc. Fibrils are not fixed to the substance of the tendons themselves, but to their membranes. The connection of the membranes with one another. Certain difficulties concerning the animalcules of the masculine seed are resolved. Seminal animalcules found in the wombs of dogs and rabbits. The ovary theory is exploded.

LETTER XXIV. Page 212

ON the scales of fish. Every year a new scale grows beneath the previous scales. From those scales, the age of fish can be estimated. At a certain time of year, all growth of bodies ceases. A great number of small eggs in female fish. A much greater number of animalcules in the seed of the male fish. Fish feed on fish. Large and voracious fish are devoid of eggs. Whales are very long-lived. Fish do not die consumed by old age.