The book, which has been in print for over a decade, stated, "Email messages should be like skirts--short enough to be interesting and long enough to cover all the vital points."
A student, who did not want to be named, said, "Some students from socially and economically weaker sections have a tendency to memorise everything written in the textbooks, without realising that such analogies may legitimise casual sexism in our society."
"Thankfully, we are able to realise and question the reliability of such textbooks in our course. Why didn't anyone question this statement in this book which is being reprinted since years?" she asked.
Now, a septuagenarian, professor CB Gupta expressed regret for hurting people's sentiments and said that the analogy was taken from an article by a foreign author. "I have already deleted the statement from my book. I will also advise the publisher to remove the content before publishing a latest edition," Mr Gupta told news agency PTI.
To a question on why such an analogy was made, he said, it was a mistake on his part and he had taken the analogy from an article of a foreign author. "It was not to hurt anyone. I took the analogy from an article written by a foreign author," Mr Gupta said.
In another instance, a book which forms part of the Delhi University's history curriculum had called Bhagat Singh a "revolutionary terrorist", prompting the freedom fighter's family to raise the issue with university authorities as well as the Human Resource Development ministry.
"A textbook should be neutral and provide balanced viewpoints and leave the rest to the student to form an opinion. Such controversies will create more awareness among textbook authors," said a DU professor who wished to remain anonymous.
The Madras High Court had directed the CBSE to remove alleged objectionable content in class IX social science textbook about the Nadar community.