There is a direct correlation between testicle size and sperm production. This has been proven in all mammals, not just humans. Mostly due to the larger the testicles, the more sperm producing cells there are. Now, having said that, there are many factors that affect sperm production other than testicle size, so its very possible that someone with larger testicles is less fertile than someone with smaller testicles. There's just too many factors to make that determination.
Testicles don't really store sperm - they just produce them, then move them toward the vas deferens and ampulla which inside the body for storage and ejaculation.
Also, sperm makes up a small percentage of the volume of semen, so someone with a high sperm count doesn't have visually more semen he ejaculates. All that semen fluid is produced by other glands such as the prostate, and seminal vesicles, not the testicles. |