Fertilisation in bryophytes is considered as internal since the fertilisation occurs inside the archegonium.bryophytes are dependent on water for sexual reproduction. so called as amphibians of plant kingdom.

Introduction:
Bryophytes are a group of non-vascular plants that includes mosses, liverworts, and hornworts. They are small, herbaceous plants that grow in damp places and have a simple body structure. One of the most important features of bryophytes is their mode of fertilization.

External Fertilization:
In bryophytes, fertilization is external. This means that the sperm and egg cells are produced in separate structures and must come into contact with each other outside of the plant's body in order for fertilization to occur.

Structure of the Bryophyte:
The body of a bryophyte is made up of a stem-like structure called a sporophyte, which is attached to a leaf-like structure called a gametophyte. The gametophyte produces the sperm and egg cells, which are housed in separate structures called antheridia and archegonia, respectively.

Fertilization Process:
During fertilization, the sperm cells swim through a film of water to reach the egg cells. The water is necessary for the sperm to swim, and it is often found in the damp environments where bryophytes grow. Once the sperm reaches the egg, it fertilizes it, and a zygote is formed.

Advantages of External Fertilization:
There are several advantages to external fertilization in bryophytes. One of the most significant is that it allows for genetic diversity. Because the sperm and egg cells are produced in separate structures, individuals can exchange genetic material with each other, leading to more variation in the population. This can be especially important in small populations where genetic diversity is limited.

Conclusion:
In conclusion, fertilization in bryophytes is external, meaning that the sperm and egg cells must come into contact with each other outside of the plant's body. This process allows for genetic diversity, which is important for the survival of the population.