Step 1: Meaning of reconstitution.
Reconstitution of partnership occurs when there is a change in agreement, e.g., admission, retirement, death, or change in profit-sharing ratio.
Step 2: Legal necessity.
It is necessary to ensure fair distribution of rights and liabilities among partners. Without reconstitution, old terms would remain unfair.
Step 3: Conclude.
Therefore, reconstitution of partnership is necessary.
Final Answer:
\[
\boxed{\text{Necessary}}
\]