4O GLOSSARY. 



Dice'cious (Gr. dis, double ; otkia, a house). Having the sexes 



in two separate individuals ; applied also to plants having 



female flowers on one individual and male flowers on 



another of the same species. 

 Diop'trics (Gr. dioptomai, I see through). The branch of the 



science of light which treats of refraction. 

 Diphycer'cal (Gr. diphues, mixed, two-fold ; kerkos, a tail). 



Applied to the tails of fishes when the extremity of the 



spine divides the caudal fin-rays into two equal or nearly 



equal parts. 

 Diplo'e (Gr. diploos, double). The spongy texture in tubular 



bones, so called because enclosed between two plates of 



compact bony tissue. 

 Dip'noi (Gr. dis, double ; pneo, I breathe). A group of fishes 



closely approximating to the Amphibia. 

 Dip'tera (Gr. dipteros, having two wings). The subdivision of 



the Insecta which comprises the flies and fleas. 

 Discoi'dea (Gr. diskos, a disc or quoit). A subdivision of the 



deciduate mammalia in which the placenta forms a thick 



disc. 

 Diseo'phora (Gr. disk&s, a disc or quoit ; phoreo, I bear). A 



group of Hydrozoa, comprising amongst other forms the 



so-called " jelly-fish." 

 Dis'cus proli'gerus (L. discus, a quoit; proles, progeny ; gero, I 



bear). The thickened portion of the granular lining of a 



Graafian follicle in which the ovum is embedded. 

 Disdi'aclast (Gr. dis, twice; diaklao, I break). A term given 



to the segments produced in cell division. 

 Dis'taL The part of a muscle, nerve, or other organ which is 



most distant .from the origin or from a fixed point. 

 Diure'tic (Gr. dia, through; oureo, to pass water). Having the 



property of increasing the secretion of urine. 

 Diverti'culum (L. a by-road). A pouch-like process given off 



from any principal passage or canal. 



Dol'ichosau'ria (Gr. dolichos, long; sauros,*. lizard). A sub- 

 division of the Lacertilia, now extinct, of which the only 



known form (Dolichosaurus) has a greatly elongated 



body. 

 Dor'sal (L. dorsum,ftiK. back). Relating to the back; opposite 



to the belly. 

 Dromseog'nathae (Gr. dromaios, running, swift ; gnathos, a jaw). 



A subdivision of Carinate birds. 

 Duct of Bar'tholin. One of the ducts of the sublingual gland. 



