Pl. -mi. Also (in sense 3) in Gr. form thalamos. [L. thalamus, a. Gr. θάλαμος an inner chamber.]
1. Anat. A part of the brain at which a nerve originates or appears to originate; spec. the OPTIC thalamus.
[1704. J. Harris, Lex. Techn., I. Thalami Nervorum Opticorum, are two Prominences of the lateral Ventricles of the Cerebrum; so call’d, because the Optick Nerves rise out of them.]
1756. Gentl. Mag., XXVI. 517/1. The thalami here appeared very thin, and the pia mater … was overspread with blood-vessels of an unusual size.
1856. Todd & Bowman, Phys. Anat., II. 38. Each tract adheres to the outer side of its corresponding thalamus for some distance.
1879. St. George’s Hosp. Rep., IX. 513. An abscess … in the right optic thalamus, opening just behind the tænia.
2. Bot. a. The receptacle of a flower, on which the carpels are placed; the torus. b. See quot. 1842.
1753. Chambers, Cycl. Supp., Thalamus, in botany, a term used to express that part of the flower … where the embryo fruits … are lodged, and where afterwards the seeds are contained.
1766. Lee, Introd. Bot., Gloss., Thalamus,… the Receptacle.
1842. Penny Cycl., XXIV. 274/1. Thalamus is also used in Cryptogamic botany, in common with Thallus, to express the bed of fibres from which many fungi spring up.
1861. Bentley, Man. Bot. (1870), 208. The extremity of the peduncle or pedicel … is called the Thalamus, or some times, but improperly, the Receptacle.
3. Archæol. An inner or secret chamber.
1850. Leitch, trans. C. O. Müller’s Anc. Art, § 48. The thalami, secret chambers for the women.
1884. Times, 15 Aug., 4. The same pattern as that found on the roof of the thalamos.
