An Introduction to the study of zoology, illustrated by the crayfishD. Appleton, 1901 - 371 pagini |
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Pagina vii
... means of directing the attention of observers in all parts of the world to the crayfishes . Combined efforts will soon furnish the answers to many questions which a single worker can merely state ; and , by completing the history of one ...
... means of directing the attention of observers in all parts of the world to the crayfishes . Combined efforts will soon furnish the answers to many questions which a single worker can merely state ; and , by completing the history of one ...
Pagina 3
... means of investigation . The course of nature as it is , as it has been , and as it will be , is the object of scientific inquiry ; whatever lies beyond , above , or below this , is outside science . But the philosopher need not despair ...
... means of investigation . The course of nature as it is , as it has been , and as it will be , is the object of scientific inquiry ; whatever lies beyond , above , or below this , is outside science . But the philosopher need not despair ...
Pagina 6
... bottom of the shallow waters which they prefer , by means of four pairs of jointed legs ( fig . 1 ) ; but , if alarmed , they swim MALE AND FEMALE CRAYFISHES . 7 backwards with rapid jerks. 6 THE NATURAL HISTORY OF THE COMMON CRAYFISH .
... bottom of the shallow waters which they prefer , by means of four pairs of jointed legs ( fig . 1 ) ; but , if alarmed , they swim MALE AND FEMALE CRAYFISHES . 7 backwards with rapid jerks. 6 THE NATURAL HISTORY OF THE COMMON CRAYFISH .
Pagina 7
... means to be des- pised , and indicates a good deal of disposable energy . A sort of shield covers the front part of the body , and ends in a sharp projecting spine in the middle line ( r ) . On each side of this is an eye , mounted on a ...
... means to be des- pised , and indicates a good deal of disposable energy . A sort of shield covers the front part of the body , and ends in a sharp projecting spine in the middle line ( r ) . On each side of this is an eye , mounted on a ...
Pagina 7
... bottom of the shallow waters which they prefer , by means of four pairs of jointed legs ( fig . 1 ) ; but , if alarmed , they swim MALE AND FEMALE CRAYFISHES . 7 backwards with rapid jerks. 6 THE NATURAL HISTORY OF THE COMMON CRAYFISH .
... bottom of the shallow waters which they prefer , by means of four pairs of jointed legs ( fig . 1 ) ; but , if alarmed , they swim MALE AND FEMALE CRAYFISHES . 7 backwards with rapid jerks. 6 THE NATURAL HISTORY OF THE COMMON CRAYFISH .
Termeni și expresii frecvente
abdomen abdominal appendages abdominal somite acid alimentary ambulatory limbs animals antenna antennule aperture appears artery arthrobranchiæ Astacine attached basal joint base become blastomeres blood body branchiæ branchial cavity branchial chamber branchial filaments branchiostegite canal carapace cephalic cephalothorax cervical groove chitinous convex corpuscles coxopodite crayfish Crustacea cuticle cuticular division ecdysis ectoderm ectostracum edge endopodite endosternites epiblast epimeral epipodite exopodite exoskeleton external fact fibres food-yelk forceps front ganglion gastrolith gills gives rise green gland hind-gut hypoblast inner lamina lateral less lobes lobster longitudinal male mandibles maxillipede membrane metameres morphological muscles muscular Nauplius nerve nobilis nucleated cells nuclei organs outer ovum pairs plate pleura podobranchiæ portion posterior present procephalic protopodite region ridge rostrum scaphognathite segments seta setæ side somite species spines stem sternal sternum stomach structure substance surface telson tergal tergum terminal thoracic thoracic limbs thoracic somite tissue transverse wall yelk