‘The Fly’ by Katherine Mansfield employs various symbols to convey deeper meanings and themes within the narrative. Following are some of the key symbols in the story and their interpretations:

1. The Fly: The central symbol in the story is the fly itself. It carries multiple layers of symbolism, representing different themes and ideas:

Symbol of Mortality: The fly's life cycle, from struggling to death, serves as a microcosm of human mortality. The boss's fascination with the fly's struggle reflects his preoccupation with the fragility of life and the inevitability of death.

Symbol of Resilience: The fly's repeated attempts to clean itself, even after being submerged in ink, symbolize resilience and the human spirit's capacity to endure adversity. This contrasts with the boss's inability to overcome his grief, highlighting the fly's strength in the face of challenges.

Metaphor for the Boss and His Son: The fly can also be seen as a metaphor for the boss and his son. The boss, like the fly, is stuck in a cycle of emotional struggle, unable to move on from his son's death. The fly's ultimate death can be seen as a reflection of the boss's inability to break free from his grief.

2. Ink: The ink in the story represents the unpredictability of life and the inevitability of death. The boss uses ink to test the fly's resilience, just as life tests human beings. The ink's unpredictable drops symbolize the uncontrollable nature of fate, and the boss's experiment with the fly becomes a metaphor for the randomness of life's challenges.

3. The Son's Photograph: The photograph of the boss's son in uniform is a symbol of both his presence and absence. It represents the son's life, vitality, and the potential he had to inherit the family business. However, the photograph's stern expression, which the boss finds unnatural, also hints at the emotional distance between the father and the son. The photograph serves as a reminder of the loss and the son's unfulfilled potential.

4. The Telegram: The telegram announcing the son's death is a symbol of the abrupt and devastating nature of loss. It represents the moment when the boss's world was shattered and the grief that has lingered ever since. The telegram is a powerful reminder of the past and a trigger for the boss's emotional turmoil.

5. The Paper and Blotting Paper: The paper stained by ink and the blotting paper represent the need to cleanse or erase painful memories and emotions. The boss calls for fresh paper to replace the stained one, reflecting his desire to start anew and find relief from his grief. The blotting paper also symbolizes the boss's futile attempts to blot out or suppress his emotions.

6. The Office and Isolation: The boss's office and his self-imposed isolation within it symbolize his emotional and psychological separation from others. He isolates himself to deal with his grief privately but remains disconnected from his employees and his own emotions. The office represents a space of emotional confinement and distance.

Overall, ‘The Fly’ uses these symbols to convey the themes of mortality, grief, resilience, and the challenges of coping with loss. The fly, in particular, acts as a multifaceted symbol that encapsulates the story's central ideas, while other symbols contribute to the overall richness and complexity of the narrative.