122 EXPLANATION OF TERMS 



an insect or of any articulate is a transverse portion reaching entirely 

 across the body, originally separated on the exterior by incisions or sutures 

 from the preceding and the succeeding segments, having attached to it not 

 more than one pair of ventral appendages, containing internally not more 

 than one pair of nerve ganglia which supply nerves to the pair of append- 

 ages ; = somite, arthromere : fusion of segments frequently obscures, as 

 in the head : externally the walls of one segment may be composed of a 

 number of sclerites separated from each other by secondary sutures. 



Segmentate: made up of rings or segments. 



Segmentation of egg: the division of the originally single-celled egg into a 

 number of coherent cells or blastomeres ; = cleavage. 



Segregated: detached or scattered into groups. 



Segregation: a separation or placing apart. 



Sejunctus: separated. 



Sellate: saddle-shaped. 



Sematophore: a seminal packet, composed of the seminal fluid mixed with 

 the excretions of the accessory glands. 



Sembling: = assembling; q. v. 



Semen: the fluid secreted in the testes, containing the spermatozoa. 



Semi-: half. 



Semicircular: like the half of a circle. 



Semi-complete: in metamorphosis, = incomplete; q. v. 



Semicordate: half or partly heart-shaped. 



Semicoronate: partly surrounded by a margin of spines, hooks or the like. 



Semicoronet: a margin of spines or hooks partly surrounding a structure or 

 process. 



Semi-cylindrical: like a groove or half a cylinder. 



Semi-hyaline : hyaline in part only : not altogether transparent. 



Semi-looper: a caterpillar in which one or two pairs only of the abdominal 

 legs are wanting and where in progression only small loops are formed : 

 see looper. 



Semi-lunar: in the form of half a crescent. 



Semi-lunar valve: guards the auriculo-ventricular opening of the heart. 



Seminal ducts: = vasa deferentia; q. v. 



Seminal vesicles: enlarged tube, or pouch-like structures which serve to store 

 the seminal fluid of the male, and in which the later stages of its develop- 

 ment may take place. 



Seminiferous: semen-secreting. 



Semipupa: that stage of the larva just preceding pupation: more specifically 

 the interpolated stage between the active larva and the true pupa, in hyper- 

 metamorphosis. 



Semi-sagittate: like the longitudinal half of an arrow head. 



Semitropical or Gulf strip: is the southern part of the Austro-riparian area; 

 extends from Texas to Southern Florida, covers a narrow strip in So. 

 Georgia and probably follows the coastal lowlands into South Carolina. 



Sensim: gradually. 



Sensoria: the circular openings covered by membrane, on the antennae or 

 legs of plant lice. 



