Sj, Sj, S3. — Sj : The immediate, self-bred, progeny of a plant 

 (typically of a non-hybrid plant). Sg: the generation pro- 

 duced by sowing seed of an S^. S3 : the progeny of an S^, etc. 



Salivary Gland Chromosomes. — Chromosomes in the nuclei 

 of the salivary gland cells in Diptera. These chromosomes have 

 undergone complete somatic pairing; consequently what is 

 ordinarily called a salivary gland chromosome is thus really 

 two chromosomes fused side by side (White). 



Salpingectomy. — A form of sterilization accomplished by 

 cutting and ligature of the oviducts. 



Saltant. — A new subdivision, type, or individual arising sud- 

 denly by mutation. 



Saltation. — A discontinuous variation produced by muta- 

 tion; a mutation. 



Sarothrum. — Pollen-brush of insects. 



SAT-chromosome. — A chromosome possessing one or more 

 satellites, or a chromosome associated with the formation 

 of the nucleolus; the letters SAT stand for 'sine acido thy- 

 monucleinico'. 



Satellite. — A short segment of chromosome separated from 

 the main body by one or more constrictions; trabant. 



Saturation. — The complete absorption of the 'pairing-attrac- 

 tion' force of one chromosome by its homologous partner 

 during pachytene pairing, as opposed to the absence of satu- 

 ration at zygotene when several homologous chromosomes can 

 be associated together as a multivalent. 



S-bivalent. — A bivalent with a subterminal centromere. 



Schizogenesis. — Reproduction by binary fission. 



S-chromosome. — A chromosome with a sub-terminal centro- 

 mere. 



Scion. — The aerial portion of a plant, which is being pro- 

 pagated by grafting onto the rooted portion, or stock, of 

 another plant. 



Scopa. — The posterior metatarsal pollen brush of bees. 



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