"The former conviction that these two kingdoms were wholly different in structure, in function, and in kind of life, was not seriously disturbed by the difficulties which the naturalist encountered when he undertook to define them"

Asa Gray's quote addresses a turning point in the history of biological category and understanding. The "2 kingdoms" he refers to are likely the animal and plant kingdoms, traditionally thought about the main categories of life kinds. Gray notes that there was a "previous conviction" or a widely accepted belief that these kingdoms were completely distinct from one another in a number of aspects: their structure (the physical and anatomical differences), function (how they sustain life and add to the environment), and sort of life (the essence or nature of their presence).

Gray highlights that in spite of this company belief in their total separation, naturalists-- the scientists who study plants and animals-- dealt with substantial challenges when they tried to specify and demarcate these kingdoms. The word "troubles" suggests that naturalists experienced numerous exceptions and ambiguities that complicated their efforts to create specific differences in between the two groups.

This observation by Gray hints at the intricacy and interconnectedness of life that was ending up being significantly evident in his time. It highlights the constraints of rigid category systems in recording the nuances of nature. The quote might also reflect early acknowledgment of evolutionary theory's ramifications, where a fluid spectrum of life types challenged the notion of strictly different categories.

Moreover, Gray's declaration discuss the developing nature of clinical understanding. As more discoveries were made, such as the identification of bacteria and the arrival of hereditary research, the lines in between various life types ended up being blurred, requiring re-evaluation of formerly held beliefs. This evolution in thought motivates openness and flexibility in clinical questions, advising naturalists to reassess and improve their classifications because of new proof and point of views.

In essence, Gray's words promote a more flexible and holistic understanding of biology, acknowledging the obstacles and complexities scientists deal with while illuminating the detailed tapestry of life in the world.