"Diagrammatic representation of a block of pine wood highly magnified. a, Early growth; b, late growth;…
"Diagram showing the relation of the water-carrying tissues of the leaves to those of the stem, and…
"Diagram to show the architecture of a typical leaf in the region of one of the lateral veins. The shaded…
"Cystoliths from the leaf of Ficus carica. A, complete cystolith; B, cystolith from which the calcium…
"If the walls of the valley contain strata of unequal hardness, the form is modified by the projection…
"The line AB represents the surface of a water wave whose length is ai, moving in the direction of the…
"1. Lower mandible. 2. Upper mandible. 3. Forehead. 4. Loral space. 5. Crown of the head. 6. Hind part…
"Rain gauges are usually vertically placed sheet-metal hollow cylinders of from 5 to 8 inches in diameter.…
Of the sorrel family (Oxalidaceae), the yellow wood or lady's sorrel (Oxalis stricta), hairy in all…
This image "represents a cross section through the ejector with the magazine loaded. The parts shown…
This image "shows a cross section through the magazine empty, and with cut-off "on," shown in projection.…
"Diagram of cell structure. Pl. Plastids in cytoplasm. cc. Centrosome. n. Nucleolus. Chr. Chromosomes.…
"Vorticella. 1. Structure. N., Macronucleus; n., micronucleus; c.v., contractile vacuole; m., mouth;…
"Diagram of a typical Hydrozoan polyp. EC., Ectoderm; EN., endoderm; C., the cavity of the gut (coelenteron);…
"Structure of a Medusoid. ST., Stomach; M., manubrium; V., velum; T., tentacle; C.C., circumference…
"Vertical section of Aurelia. m., Mouth; st., stomach; r.c., radial canal; R., reproductive organs;…
"Diagram of Lucernaria. C., Cavity of gut (colenteron); F., gastric filaments; H. hypostome; G., gonad;…
"Vertical section of a sea anemone. t., Tentacles; o., mouth; oes., oesophagus; c., c'., apertures through…
"Section through sea anemone. A, B, Directive septa; m.f., mesenteric filaments; g., genital organs;…
"The formation of a coral shell (Asteroides). st., Stomodaeum; ms., mesentery; s., calcareous septum;…
"Diagram of a gymnoblastic Hydroid. a., Stem; b., root; c., gut cavity; d., endoderm (dark); e., ectoderm;…
"Campanularian Hydroid. H., Hydrotheca or polyp-cup; HY., hydranth, or polyp-head; G., gonotheca, enclosing…
"Diagram of a Ctenophore. M., Mouth; S., sensory organ; T., tentacle cut short; SH., pouch of tentacle;…
"Hydroctena. A medusoid with suggestion of Ctenophore structure, but a true medusoid nonetheless. ab.o.…
"B., one of the characteristic hollow flame-cells, leading into the excretory tubule (1), showing the…
"Life history of Taenia solium. 1. Six-hooked embryo in egg-case; 2. proscolex or bladder-worm stage,…
"Diagrammatic longitudinal section of a Nemertean (Amphiporum lactifloreus), dorsal view. p.p., Proboscis…
"Cross-section through Ascaris. d.n., Dorsal nerve; n.c., non-contractile portion of muscle cells; c.,…
"Diagram of the structure of a male Nematode. M., mouth; OE., oesophogus; GA., nerve ring; B., bulb…
"Transverse section of earthworm. A., Cuticle; B., epidermis; C.M., circular muscles; L.M., longitudinal…
"Reproductive organs of earthworm. N., Nerve cord; T., anterior testes; S., sacs of setae; R.S., receptacula…
"Dissection of lob-worm from dorsal surface. m., Opening of retracted buccal cavity; i., gullet; gl.,…
"Cross-section of Arenicola. E., Epidermis; c.m., circular muscles; l.m., longitudinal muscles; b.c.,…
"Transverse section of leech. c., Cuticle; e., epidermis; c.m., dermis and outer muscles (circular and…
"Alimentary system of leech. m., Mouth; cr6., sixth crop-pocket; cr11., last crop-pocket; v., rectum;…
"Dissection of leech. c.g., Cerebral ganglia; p., penis; s.v. is opposite the semminal vesicle; ov.,…
"Diagram of an Ectoproctous Polyzoon (Plumatella). L., Lophophore; PH., pharynx; A., anus; S., stomach;…
"Starfish. I. Ventral surface; t.f., tube-feet extended; a.g., the ambulacral groove with the tube-feet…
"Diagrammatic cross-section of starfish arm. n., Radial nerve; b.v., radial blood vessel according to…
"Ventral surface of disc of an Ophiuroid (Ophiothrix fragilis). g., Openings of genital pockets or bursae;…
"Apical disc of sea-urchin. In the centre is the periproct bearing the anus; around it are five genital…
"Dissection of Holothurian (Holothuria tubulosa) from the ventral surface." t, tentacles; tf, scattered…
"Diagrammatic vertical section through disc and base of one of the arms of Antedon rosacea. The section…
"Appendages of Norway lobster. Ex., Exopodite: En., endopodite; protopodite dark throughout; Ep., epipodite.…
"Longitudinal section of lobster, showing some of the organs. H., Heart; AO., ophthalmic artery; SA.,…
"Section through cephalothorax of a crab. H., Heart; Te., extension of the tergum; ST., sternum; PL.,…
"Dorsal aspect of swimming crab (Portunus). P., Paddle; Abd., abdomen; A1., antennules; A2., antennae;…
"Dorsal aspect of shore crab (Carcinnus). Abd., Abdomen; A1., antennules; A2., antennae; E., eyes; F.,…
"Ventral aspect of femal shore crab. Abd., Abdomen; mxp., third maxillipede." -Thomson, 1916
"Acorn-shell (Balanus tintinnabulum). T., tergum; CR., thoracic legs; R., outer shell in section; D.,…
"Nebalia. SH., Shell; A.1, first antennae; A.2, second antennae; TH., 8 thoracic limbs; Ab.4, Ab.6,…
"Hermit-crab withdrawn from its shell. The anterior appendages are broken off. hd., Head; th., thorax;…
"Dissection of Peripatus. at., Antennae; or.p., oral papillae; c.g., cerebral ganglia; sl.d., duct of…
"Ventral aspect of male cockroach with the wings extended. An imaginary median line has been inserted.…
"Leg of cockroach. c., Broad expanded coxa; tr., trochanter; f., femur; ti., tibia; ta., six-jointed…
"Transverse section of insect. h., Heart; g., gut; n., nerve-cord; st., stigma; tr., trachea; w., wing;…
"Head and mouth parts of bee. a., Antenna; m., mandible; g., labrum or epipharynx; mx.p., rudiment of…
"Mouth-parts of mosquito. a., Antennae; lxe., labrum and epipharynx; mn., mandibles; hp., hypopharynx;…