Robert Brown
A botanist who discovered the nucleus in plant cells and described Brownian motion, the random movement of particles in a fluid.
Most quoted
"I have, however, been enabled to satisfy myself that the particles or molecules of the pollen of plants, and indeed of many other organic as well as inorganic bodies, when suspended in water, are in a state of constant and rapid oscillatory motion."
— from A Brief Account of Microscopical Observations Made in the Months of June, July, and August, 1827, on the Particles Contained in the Pollen of Plants; and on the General Existence of Active Molecules in Organic and Inorganic Bodies., 1827
"This motion was such as to satisfy me, after frequently repeated observation, that it was not caused either by currents in the fluid, or by its gradual evaporation, but belonged to the particle itself."
— from A Brief Account of Microscopical Observations Made in the Months of June, July, and August, 1827, on the Particles Contained in the Pollen of Plants; and on the General Existence of Active Molecules in Organic and Inorganic Bodies., 1827
"This motion was such as to satisfy me, after frequently repeated observation, that it arose neither from currents in the fluid, nor from its gradual evaporation, but belonged to the particle itself."
— from A Brief Account of Microscopical Observations Made in the Months of June, July, and August, 1827, on the Particles Contained in the Pollen of Plants; and on the General Existence of Active Molecules in Organic and Inorganic Bodies, 1827
All quotes by Robert Brown (343)
The nucleus is a constant and highly characteristic constituent of the vegetable cell.
This nucleus, or areola, as it is sometimes called, is present in the cells of all plants, and appears to be essential to their vitality.
The nucleus is a primary constituent of the cell, and is probably concerned in its formation and development.
The ovulum, or embryo-sac, is not a mere cavity, but a distinct organ, containing the germ of the future plant.
The pollen-tube penetrates the stigma, and conveys the fertilizing matter to the ovulum.
The process of fecundation in plants is analogous to that in animals.
The ovulum is not merely a receptacle for the pollen, but an organized body, in which the embryo is developed.
The development of the embryo takes place within the ovulum, after the application of the pollen.
The true nature of the ovulum has been generally misunderstood.
The structure of the ovulum is more complex than has been generally supposed.
The pollen-tube is not merely an appendage, but an active agent in fecundation.
The observations on the pollen-tube confirm the analogy between vegetable and animal generation.
The existence of a distinct nucleus in the cells of plants is a fact of considerable importance.
The nucleus is a constant and essential part of the vegetable cell, and is probably concerned in its growth and reproduction.
The nucleus is not a mere accidental inclusion, but an organized body, having a definite structure and function.
The discovery of the nucleus has opened a new field of inquiry into the nature and functions of the vegetable cell.
The nucleus is a fundamental element in the organization of plants.
The motion of the particles is independent of any external cause, and appears to be inherent in the particles themselves.
The motion is not a vital phenomenon, but a physical one.
The motion is not caused by any attractive or repulsive forces between the particles.
Contemporaries of Robert Brown
Other Biologys born within 50 years of Robert Brown (1773–1858).