The construction depicted in the picture is from the 2nd JM; at this time copulation had long been a strictly controlled action that involved will, i.e. regulated behavior.
Those functions translated in the interactions among corpuscles to experiences of desire as well as fear, which were associated, respectively, with the more complex "motivation" and a shared "sense of prohibition". The novel motivation was indicated verbally by the sound "drive", replacing the "instinct".
The average H. Sapiens bolstered the experience of drive fulfillment by avoiding or delaying it. Now fulfillment was pleasure--a stronger reward.
The interplay between the brain reward circuits and other parts of the corpuscle were involved in the delay, avoidance, and augmentation of pleasure.
Copulation came to be strongly associated with several auditory and visual symbols as control over it tightened. The efficiency afforded by the cascade was fascinating--hence the meme characteristic of sexual reproduction.
Castration was one of the powerful symbols derived from the memes that materialized around this instinct and paved the way to many others.
For a better understanding of reproduction in the late Earthian corpuscle, specifically the minority H. Sapiens, we will in the next chapter have a glimpse at some of the 20th century European scripts: A series of brief narratives, collectively termed as psychoanalysis, provides rich clues in this context. It is of note that traces of this system can be detected millenia later in life sciences. Perhaps we have yet to learn from the 2nd JM Earthian corpuscle.