W. J. Els

• Contributions to the morphology and histology of the genital system of the pulmonate Cochlicella ventricosa (Draparnaud)
• Histochemical studies on the maturation of the genital system of the slug Deroceras laeve, (Pulmonata, Limacidae) with special reference to the identification of mucosubstances secreted by the genital tract
• Where theory meets practice